JP2008228038A - Semiconductor integrated circuit and test method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce test cost for a communication function of transmission and reception incorporated in a semiconductor integrated circuit. <P>SOLUTION: A semiconductor integrated circuit 100 includes receiving systems 4-12, transmitting systems 13-16, and an RF test signal supply circuit 18. The RF test signal supply circuit 18 converts RF transmission output signals from the transmitting systems into RF test signals of a frequency band processable for the receiving systems and supplies the converted signals to the receiving systems. The semiconductor integrated circuit 100 is set into a normal operation mode to perform transmitting/receiving operation with the receiving systems and the transmitting systems. The semiconductor integrated circuit 100 is set into the other operation mode different from the normal operation mode so that the RF test signal supply circuit 18 supplies the converted RF test signals to the receiving systems. When received signals in the receiving systems are normal during a test, it is determined that the receiving systems and the transmitting systems of the semiconductor integrated circuit 100 are normal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor integrated circuit and a test method thereof, and more particularly to a technique useful for facilitating a test of a transmission / reception communication function built in a semiconductor integrated circuit.

  Various semiconductor integrated circuits for communication having a mobile function of wireless communication by a communication terminal device such as a mobile phone terminal have been developed. These mobile systems include GSM, GPRS, EDGE, WCDMA, DCS, PCS cellular. As for the characteristics of these systems, there is a growing demand for multiband and multimode of a wide range of combinations of signals of constant envelope and envelope change, a multiplex of time division and code division. GSM is an abbreviation for Global System for Mobile Communication, and GPRS is an abbreviation for General Packet Radio Service. EDGE is an abbreviation for Enhanced Data for GSM Evolution; Enhanced Data for GPRS. WCDMA is an abbreviation for Wideband Code Division Multiple Access. DCS is an abbreviation for Digital Cellular System. PCS is an abbreviation for Personal Communication System.

  Patent Document 1 below describes a radio frequency transceiver incorporating a self-test function. The transceiver receives in either the low RF frequency band of 824-849 MHz or the high RF frequency band of 869-894 MHz, while transmitting in the high RF frequency band of 869-894 MHz. The transceiver transmitter provides a specially encoded test signal of 824-849 MHz in the low RF frequency band to the transceiver receiver. When the test signal is successfully received at the receiver, it can be determined that the transmission and reception paths of the transceiver are operating normally.

  Patent Document 2 below removes unnecessary images by adjusting the phase and amplitude of quadrature demodulated I and Q signals in a low IF receiver that converts RF received signals into low IF (low intermediate frequency) signals. The technology to do is described. In the calibration mode, the output signal of the transmission voltage controlled oscillator is supplied to the quadrature mixer to adjust the phase and amplitude.

  Further, in Non-Patent Document 1 below, the frequency band becomes overcrowded due to a rapid increase in the number of devices, and low-cost highly integrated transceivers can be produced in large quantities at low cost due to technological advances. It is described that the transition from 900 MHz to 2.4 GHz was promoted. Today, the 2.4 GHz ISM frequency band is also overcrowded by cordless phones, Bluetooth devices, 802.11b / g networks, and microwaves. It is also described in Non-Patent Document 1 below that the communication device manufacturer also activates the development of devices using the 5.8 GHz ISM frequency band.

  Also, the ISM frequency band was initially internationally reserved for non-commercial use of RF fields for industrial, scientific and medical purposes. Recently, ISM frequency bands are four frequency bands of 900 MHz, 1.8 GHz, 2.4 GHz, and 5.8 GHz, and are shared by license-free and error-resistant communication in wireless LAN, Bluetooth, and the like.

Japanese Patent Laid-Open No. 10-93488 Japanese Patent Laid-Open No. 11-251947 G. Luff et al, “A Low Cost, Highly Integrated 5.8 GHz Low-IF Transceiver for 1.5 Mbps Streaming Data Application”, 2004 IEEE RadioFrequencyIncidencePP. 343-346.

  In order to calibrate the received signal error such as mismatch of amplitude and phase component of I-phase signal and Q-phase signal with high accuracy in a short time at the receiver of the wireless communication terminal device, a test having a frequency within the reception band A signal is required. In Patent Document 2, a test signal in the RF reception band is generated from a transmission voltage controlled oscillator (Tx-VCO) when calibrating received signal errors such as amplitude and phase mismatches between the I-phase signal and the Q-phase signal. And input to the quadrature mixer circuit of the receiver.

  Prior to the present invention, the inventor engaged in the development of a semiconductor integrated circuit for communication mounted on an analog cordless telephone using a plurality of frequency bands (900 MHz, 5.8 GHz) of the ISM frequency band. In this analog cordless telephone, the slave unit receives an RF signal in a frequency band of 900 MHz from the master unit, and transmits an RF signal in a frequency band of 5.8 GHz to the master unit. The master unit connected to the fixed telephone line receives the RF signal in the frequency band of 5.8 GHz, and transmits the RF signal in the frequency band of 900 MHz to the slave unit. The communication semiconductor integrated circuit for the slave unit and the master unit can be configured with chips of different specifications, but the communication semiconductor integrated circuit that can be used in common for the slave unit and the master unit is turned on. By setting the operation mode such as, it can be set for the slave unit and the master unit. The slave unit communication semiconductor integrated circuit performs 900 MHz RF signal reception and 5.8 GHz RF signal transmission, and the base unit communication semiconductor integrated circuit performs 5.8 GHz RF signal reception and 900 MHz RF signal transmission. Do.

  In the production of a communication semiconductor integrated circuit that can be used in common with this slave unit and this master unit, the following tests were required. FIG. 16 is a diagram for explaining a test of a transmission / reception communication function as a slave unit of a semiconductor integrated circuit for communication mounted on an analog cordless telephone studied by the present inventors prior to the present invention.

  In the figure, a communication semiconductor integrated circuit 100 mounted on an analog cordless telephone includes a reception system and a transmission system. The reception system includes a low noise amplifier 4, bandpass filters 5, 8 and 11, a reception mixer 6, a reception voltage control oscillator 7, an intermediate frequency amplifier 9, an FM demodulator 10, and an output amplifier 12. The transmission system includes an input amplifier 13, an FM modulator 14, a driver 15, and an RF power amplifier 16, and the FM modulator 14 includes a transmission voltage control oscillator 14a and a modulation control unit 14b.

  A baseband signal external test device 200 and an RF signal external test device 300 are connected to the communication semiconductor integrated circuit 100. The baseband signal external test apparatus 200 includes a baseband reception signal analyzer 200A and a baseband transmission signal generator 200B, and the RF signal external test apparatus 300 includes an RF reception signal generator 300A and an RF reception signal analyzer 300B. .

  A command CMD is supplied from the baseband signal external test apparatus 200 to the command input unit 19 of the trusted semiconductor integrated circuit 100 in order to test the transmission / reception communication function as a slave unit of the communication semiconductor integrated circuit 100. This command CMD is one of a plurality of operation mode setting commands in an initialization operation such as when the power is turned on, and operates the communication semiconductor integrated circuit 100 as a slave of an analog cordless telephone.

  The 900 MHz RF test signal generated from the RF reception signal generator 300 </ b> A of the RF signal external test apparatus 300 is supplied to the input of the low noise amplifier 4 of the communication semiconductor integrated circuit 100 through the band pass filter 3. The 900 MHz RF amplified signal of the low noise amplifier 4 is supplied to one input terminal of the reception mixer 6 via the band pass filter 5. A reception carrier signal having a predetermined frequency generated from the reception voltage control oscillator 7 is supplied to the other input terminal of the reception mixer 6, and an intermediate frequency signal is generated from the output of the reception mixer 6. The intermediate frequency signal is amplified by the intermediate frequency amplifier 9 via the band pass filter 8 and then supplied to the input of the FM demodulator 10. The FM demodulated output signal generated from the FM demodulator 10 is amplified by the output amplifier 12, and then supplied to the input of the baseband received signal analyzer 200A of the baseband signal external test apparatus 200. The baseband reception signal analyzer 200A tests whether the reception function as a slave unit of the communication semiconductor integrated circuit 100 is normal by analyzing the baseband reception signal from the output amplifier 12 of the communication semiconductor integrated circuit 100. To do.

  The baseband transmission test signal generated from the baseband transmission signal generator 200B of the baseband signal external test apparatus 200 is supplied to the input of the input amplifier 13 of the communication semiconductor integrated circuit 100. The output signal of the input amplifier 13 is supplied to the modulation control unit 14b of the FM modulator 14, whereby the output frequency of the transmission voltage controlled oscillator 14a is modulated by the output signal of the modulation control unit 14b. The FM modulated RF signal having a frequency of approximately 5.8 GHz of the FM modulator 14 is amplified by the driver 15 and then supplied to the input of the RF power amplifier 16. The RF transmission signal of about 5.8 GHz of the RF power amplifier 16 is supplied to the input of the RF reception signal analyzer 300 </ b> B of the RF signal external test apparatus 300 through the band pass filter 17. The RF reception signal analyzer 300B tests whether or not the transmission function as a slave unit of the communication semiconductor integrated circuit 100 is normal by analyzing the RF transmission signal from the RF power amplifier 16 of the communication semiconductor integrated circuit 100. Is.

  FIG. 17 is a diagram for explaining a test of a transmission / reception communication function as a master unit of a communication semiconductor integrated circuit mounted on an analog cordless telephone studied by the present inventors prior to the present invention.

  A command CMD is supplied from the baseband signal external test device 200 to the command input unit 19 of the trusted semiconductor integrated circuit 100 in order to test the transmission / reception communication function as the parent device of the communication semiconductor integrated circuit 100. This command CMD is one of a plurality of operation mode setting instructions in an initialization operation such as when the power is turned on, and operates the communication semiconductor integrated circuit 100 as a master unit of an analog cordless telephone.

  The RF test signal of 5.8 GHz generated from the RF reception signal generator 300 </ b> A of the RF signal external test apparatus 300 is supplied to the input of the low noise amplifier 4 of the communication semiconductor integrated circuit 100 through the band pass filter 3. The 5.8 GHz RF amplified signal of the low noise amplifier 4 is supplied to one input terminal of the reception mixer 6 via the band pass filter 5. A reception carrier signal having a predetermined frequency generated from the reception voltage control oscillator 7 is supplied to the other input terminal of the reception mixer 6, and an intermediate frequency signal is generated from the output of the reception mixer 6. The intermediate frequency signal is amplified by the intermediate frequency amplifier 9 via the band pass filter 8 and then supplied to the input of the FM demodulator 10. The FM demodulated output signal generated from the FM demodulator 10 is amplified by the output amplifier 12, and then supplied to the input of the baseband received signal analyzer 200A of the baseband signal external test apparatus 200. The baseband reception signal analyzer 200A tests whether or not the reception function as the master unit of the communication semiconductor integrated circuit 100 is normal by analyzing the baseband reception signal from the output amplifier 12 of the communication semiconductor integrated circuit 100. To do.

  The baseband transmission test signal generated from the baseband transmission signal generator 200B of the baseband signal external test apparatus 200 is supplied to the input of the input amplifier 13 of the communication semiconductor integrated circuit 100. The output signal of the input amplifier 13 is supplied to the modulation control unit 14b of the FM modulator 14, whereby the output frequency of the transmission voltage controlled oscillator 14a is modulated by the output signal of the modulation control unit 14b. The FM modulated RF signal having a frequency of approximately 900 MHz of the FM modulator 14 is amplified by the driver 15 and then supplied to the input of the RF power amplifier 16. The RF transmission signal of about 900 MHz from the RF power amplifier 16 is supplied to the input of the RF reception signal analyzer 300B of the RF signal external test apparatus 300 through the band pass filter 17. The RF reception signal analyzer 300B tests whether or not the transmission function as the master unit of the communication semiconductor integrated circuit 100 is normal by analyzing the RF transmission signal from the RF power amplifier 16 of the communication semiconductor integrated circuit 100. Is.

  However, according to the study by the present inventors, it has been clarified that the above test requires an expensive RF signal external test apparatus 300. In the above test, the band-pass filters 3 and 17 and the RF reception signal generator 300A and the RF reception signal analyzer 300B of the RF signal external test apparatus 300 need to be switched between a frequency of about 900 MHz and a frequency of about 5.8 GHz. There is. This switching takes time, and it has been clarified that the above test requires a long test time and a high test cost.

  Therefore, the present invention has been made on the basis of studies made prior to the present invention by the present inventors. It is another object of the present invention to reduce the test cost of a transmission / reception communication function built in a semiconductor integrated circuit.

  A representative one of the inventions disclosed in the present application will be briefly described as follows.

  That is, a typical semiconductor integrated circuit of the present invention includes a reception system that processes an RF reception input signal and a transmission system that generates an RF transmission output signal. The semiconductor integrated circuit converts the RF transmission output signal generated in the transmission frequency band by the transmission system into an RF test signal having a frequency band that can be processed by the reception system, and converts the RF test signal to the reception system. An RF test signal supply circuit (18) for supplying is further included.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  That is, according to the present invention, it is possible to reduce the test cost of the transmission / reception communication function built in the semiconductor integrated circuit.

<Typical embodiment>
First, an outline of a typical embodiment of the invention disclosed in the present application will be described. The reference numerals in the drawings referred to with parentheses in the outline description of the representative embodiments merely exemplify what are included in the concept of the components to which the reference numerals are attached.

  [1] A semiconductor integrated circuit (100) according to a typical embodiment of the present invention includes a reception system (4, 5... 12) for processing an RF reception input signal, and a transmission system for generating an RF transmission output signal ( 13 ... 16). The RF reception input signal can be set to a predetermined reception frequency band, and the RF transmission output signal can be set to a predetermined transmission frequency band different from the frequency of the reception frequency band.

  The semiconductor integrated circuit converts the RF transmission output signal generated in the transmission frequency band by the transmission system into an RF test signal having a frequency band that can be processed by the reception system, and converts the RF test signal into the reception system. The circuit further includes an RF test signal supply circuit (18) for supplying to the circuit.

  The semiconductor integrated circuit is set in a normal operation mode, so that the reception system processes the RF reception input signal set in the reception frequency band, while the transmission system is set in the transmission frequency band. An RF transmission output signal is generated.

  When the semiconductor integrated circuit is set to another operation mode different from the normal operation mode, the RF test signal supply circuit supplies the RF test signal to the reception system (see FIG. 1).

  As a preferred embodiment, the other operation mode is a test mode of the semiconductor integrated circuit. By using the RF test signal supply circuit in the other operation mode as the test mode, it is possible to test whether the transmission system and the reception system of the semiconductor integrated circuit are normal. .

  Therefore, according to the preferred embodiment, in the other operation mode, by supplying a transmission test signal from a low-cost general-purpose external test device to the reception system of the semiconductor integrated circuit, the transmission system is The RF transmission output signal set in the transmission frequency band is generated. The RF test signal supply circuit supplies the RF test signal obtained by converting the RF transmission output signal from the transmission system to the reception system. The frequency of the RF test signal can be processed by the receiving system. By analyzing the demodulated output signal generated from the reception system by a low-cost general-purpose external test device, it is possible to test whether the transmission system and the reception system of the semiconductor integrated circuit are normal (see FIG. 14, see FIG. Therefore, it is possible to reduce the test cost of the transmission / reception communication function built in the semiconductor integrated circuit.

  As another preferred embodiment, the other operation mode is a calibration mode of the semiconductor integrated circuit. By using the RF test signal supply circuit in the other operation mode as the calibration mode, it is possible to perform a calibration operation that reduces the reception error of the reception system of the semiconductor integrated circuit prior to the normal operation mode. Is.

  Therefore, according to the preferred embodiment, it is possible to perform a calibration operation for reducing the reception error of the reception system of the semiconductor integrated circuit prior to the normal operation mode.

  As a preferred mode, when the frequency of the transmission frequency band of the RF transmission output signal is set higher than the frequency of the reception frequency band of the RF reception input signal, the RF test signal supply circuit performs frequency down-conversion. Set to mode. The RF test signal is generated by the RF test signal supply circuit by converting the RF transmission output signal to a low frequency by the frequency down-conversion function of the RF test signal supply circuit (see FIG. 14). When the frequency of the transmission frequency band of the RF transmission output signal is set lower than the frequency of the reception frequency band of the RF reception input signal, the RF test signal supply circuit is set to a frequency up-conversion mode. . The RF test signal is generated by the RF test signal supply circuit by converting the RF transmission output signal to a high frequency by the function of the frequency up-conversion of the RF test signal supply circuit (see FIG. 15).

  As a more preferred form, the RF test signal supply circuit includes a phase-locked loop circuit.

  Further preferably, the RF test signal supply circuit includes a fractional phase locked loop circuit in which the frequency division number of the frequency divider can include a fraction (see FIG. 4).

  According to the further preferred embodiment, it is possible to improve the degree of freedom of frequency conversion of the RF test signal supply circuit.

  More preferably, the reception frequency band of the RF reception input signal and the transmission frequency band of the RF transmission output signal are four frequencies of 900 MHz, 1.8 GHz, 2.4 GHz, and 5.8 GHz of the ISM frequency band. Any two frequency bands can be set.

  [2] A method of testing a semiconductor integrated circuit according to another embodiment of the present invention includes a step of preparing the semiconductor integrated circuit (100) according to [1].

  In the test method, the RF test signal supply circuit reduces the frequency in order to test the operation mode when the frequency of the transmission frequency band of the RF transmission output signal is set higher than the frequency of the reception frequency band of the RF reception input signal. Including the step of setting the mode of conversion.

  The test method is generated from a receiving system that supplies a transmission test signal from an external test apparatus to the transmission system and responds to a low frequency RF test signal generated by the frequency down conversion function of the RF test signal supply circuit. The step of analyzing the received output signal by an external test device is included (see FIG. 12).

  In the test method, the RF test signal supply circuit increases the frequency to test the operation mode when the frequency of the transmission frequency band of the RF transmission output signal is set lower than the frequency of the reception frequency band of the RF reception input signal. Including the step of setting the mode of conversion.

  The test method is generated from a receiving system that supplies a transmission test signal from an external test device to a transmission system and responds to a high frequency RF test signal generated by the frequency up-conversion function of the RF test signal supply circuit. The step of analyzing the received output signal by an external test device is included (see FIG. 13).

<< Description of Embodiment >>
Next, the embodiment will be described in more detail.

<< Configuration of communication semiconductor integrated circuit usable for analog cordless telephone >>
FIG. 1 is a diagram showing a semiconductor integrated circuit for communication 100 according to one embodiment of the present invention. This communication semiconductor integrated circuit 100 can be used in common for a slave unit and a master unit of an analog cordless telephone. In an analog cordless telephone, a slave unit receives an RF signal in a frequency band of 900 MHz from the master unit, and transmits an RF signal in a frequency band of 5.8 GHz to the master unit. The master unit connected to the fixed telephone line receives the RF signal in the frequency band of 5.8 GHz, and transmits the RF signal in the frequency band of 900 MHz to the slave unit. A communication semiconductor integrated circuit that can be used in common with the slave unit and the master unit can be set for the slave unit and the master unit by setting an operation mode when the power is turned on. The slave unit communication semiconductor integrated circuit performs 900 MHz RF signal reception and 5.8 GHz RF signal transmission, and the base unit communication semiconductor integrated circuit performs 5.8 GHz RF signal reception and 900 MHz RF signal transmission. Do.

  The communication semiconductor integrated circuit 100 shown in FIG. 1 includes a reception system and a transmission system as in FIG. The reception system includes a low noise amplifier 4, bandpass filters 5, 8 and 11, a reception mixer 6, a reception voltage control oscillator 7, an intermediate frequency amplifier 9, an FM demodulator 10, and an output amplifier 12. The transmission system includes an input amplifier 13, an FM modulator 14, a driver 15, and an RF power amplifier 16, and the FM modulator 14 includes a transmission voltage control oscillator 14a and a modulation control unit 14b. Compared with FIG. 16, the communication semiconductor integrated circuit 100 shown in FIG. 1 further includes an RF test signal supply circuit 18. The RF test signal supply circuit 18 converts the RF transmission output signal generated in the transmission frequency band by the transmission system (13... 16) into an RF test signal having a frequency band that can be processed by the reception system (4... 12). An RF test signal is supplied to the receiving system (4... 12).

  When the communication semiconductor integrated circuit 100 is set to the normal operation mode, the reception system (4... 12) processes the RF reception input signal set in the reception frequency band, while the transmission system (13... 16) transmits. An RF transmission output signal set in the frequency band is generated.

  When the communication semiconductor integrated circuit 100 is set to another operation mode different from the normal operation mode, the RF test signal supply circuit supplies the RF test signal to the reception system.

  When the frequency of the transmission frequency band of the RF transmission output signal from the RF power amplifier 16 is set higher than the frequency of the reception frequency band of the RF reception input signal to the low noise amplifier 4, the RF test signal supply circuit 18 reduces the frequency. Set to conversion mode. An RF test signal is generated by the RF test signal supply circuit 18 when the RF transmission output signal is converted to a low frequency by the frequency down-conversion function of the RF test signal supply circuit 18, and is supplied to the low noise amplifier 4 of the reception system. The

  When the frequency of the transmission frequency band of the RF transmission output signal from the RF power amplifier 16 is set lower than the frequency of the reception frequency band of the RF reception input signal to the low noise amplifier 4, the RF test signal supply circuit 18 increases the frequency. Set to conversion mode. By the frequency up-conversion function of the RF test signal supply circuit 18, the RF transmission output signal is converted to a high frequency so that the RF test signal is generated by the RF test signal supply circuit 18 and supplied to the low noise amplifier 4 of the reception system. The

  When the frequency of the transmission frequency band of the RF transmission output signal from the RF power amplifier 16 is set higher than the frequency of the reception frequency band of the RF reception input signal to the low noise amplifier 4, the RF test signal supply circuit 18 reduces the frequency. Set to conversion mode. An RF test signal is generated by the RF test signal supply circuit 18 when the RF transmission output signal is converted to a low frequency by the frequency up-conversion function of the RF test signal supply circuit 18, and is supplied to the low noise amplifier 4 of the reception system. The

<< Configuration of RF test signal supply circuit >>
The RF test signal supply circuit 18 can have both a frequency down-conversion function and a frequency up-conversion function. As shown in the lower part of FIG. 1, the RF test signal supply circuit 18 is constituted by a phase-locked loop (PLL) circuit. The PLL circuit includes a first frequency divider 18a to which an RF transmission output signal from the RF power amplifier 16 is supplied to an input, and an output signal of the first frequency divider 18a is supplied to one input terminal of the phase comparator 18b. The output signal of the second frequency divider 18f is supplied to the other input terminal of the phase comparator 18b. The output signal of the phase comparator 18b is supplied to the input of the voltage controlled oscillator 18d through the charge pump 18c and the loop filter 18d, and the output signal of the voltage controlled oscillator 18e is supplied to the input of the second frequency divider 18f.

  In the test mode, the output signal of the voltage controlled oscillator 18e is supplied as an RF test signal from the RF test signal supply circuit 18 to the input of the low noise amplifier 4 of the receiving system. As a result, it is possible to reduce the test cost of the receiving system (4... 12) and the transmitting system (13... 16).

<Operation of communication semiconductor integrated circuit as slave unit>
When the communication semiconductor integrated circuit 100 is used for either a slave unit or a master unit of an analog cordless telephone, a duplexer 2 is connected to the antenna 1. The duplexer 2 supplies an RF reception input signal from the antenna 1 to the low noise amplifier 4 of the reception system and supplies an RF transmission output signal from the RF power amplifier 16 of the transmission system to the antenna 1. Further, the duplexer 2 supplies an RF reception input signal and an RF transmission output signal by a frequency-division multiple access (FDMA) method.

  When the communication semiconductor integrated circuit 100 is used for a slave unit of an analog cordless telephone, a command CMD is supplied from the slave unit to the command input unit 19 of the communication semiconductor integrated circuit 100 by an initialization operation when the power is turned on. The The command CMD is an operation mode setting command for operating the communication semiconductor integrated circuit 100 as a slave unit of the analog cordless telephone. In that case, an RF reception signal in the 900 MHz frequency band of the ISM frequency band transmitted from the parent device and received by the antenna 1 is input to the low noise amplifier 4 of the communication semiconductor integrated circuit 100 via the band pass filter 3. Supplied. The 900 MHz RF amplified signal of the low noise amplifier 4 is supplied to one input terminal of the reception mixer 6 via the band pass filter 5. A reception carrier signal having a predetermined frequency generated from the reception voltage control oscillator 7 is supplied to the other input terminal of the reception mixer 6, and an intermediate frequency signal is generated from the output of the reception mixer 6. The intermediate frequency signal is amplified by the intermediate frequency amplifier 9 via the band pass filter 8 and then supplied to the input of the FM demodulator 10. The FM demodulated output signal generated from the FM demodulator 10 is amplified by the output amplifier 12 and then supplied to the speaker of the slave unit.

  The audio signal from the microphone of the slave unit is supplied to the input of the input amplifier 13 of the communication semiconductor integrated circuit 100. The output signal of the input amplifier 13 is supplied to the modulation control unit 14b of the FM modulator 14, whereby the output frequency of the transmission voltage controlled oscillator 14a is modulated by the output signal of the modulation control unit 14b. The FM modulated RF signal having a frequency of approximately 5.8 GHz of the FM modulator 14 is amplified by the driver 15 and then supplied to the input of the RF power amplifier 16. An RF transmission signal of approximately 5.8 GHz from the RF power amplifier 16 is transferred to the parent device via the bandpass filter 17 and the antenna 1 of the child device.

《Operation test of communication semiconductor integrated circuit as slave unit》
Whether or not the reception system (4... 12) and the transmission system (13... 16) of the communication semiconductor integrated circuit 100 operate normally when the communication semiconductor integrated circuit 100 is used as a slave unit of an analog cordless telephone. It is necessary to carry out such a test.

  At this time, the command CMD is supplied from the external test apparatus to the command input unit 19 of the communication semiconductor integrated circuit 100 by an initialization operation such as when the power is turned on. This command CMD is a slave unit test for testing whether the reception system (4... 12) and the transmission system (13... 16) of the communication semiconductor integrated circuit 100 used for the slave unit operate normally. This is a command to set the operation mode.

  FIG. 2 is a diagram for explaining the operation of the RF test signal supply circuit 18 of the communication semiconductor integrated circuit 100 of FIG. 1 in response to the command for setting the slave unit test operation mode. In this case, in the RF test signal supply circuit 18, the first frequency division number N of the first frequency divider 18a is set to “6”, and the second frequency division number M of the second frequency divider 18f is “1”. "Is set. Therefore, the RF test signal supply circuit 18 operates as a frequency divider having a frequency division number “6”.

  In this case, the RF power amplifier 16 of the communication semiconductor integrated circuit 100 generates an RF transmission signal of 5802 MHz within the frequency band of 5.8 GHz of the ISM frequency band, and is input to the RF test signal supply circuit 18. Supplied. Accordingly, a 967 MHz RF test signal close to the 900 MHz frequency band of the ISM frequency band is generated from the output of the RF test signal supply circuit 18 and supplied to the input of the low noise amplifier 4 of the communication semiconductor integrated circuit 100.

  FIG. 14 is a diagram for explaining the test operation of the communication semiconductor integrated circuit 100 of FIG. 1 using the setting command to the slave unit test operation mode.

  An RF transmission signal of 5802 MHz is generated from the RF power amplifier 16 in response to the setting command to the slave unit test operation mode, and the operation mode of the RF test signal supply circuit 18 is the operation of the frequency divider having the frequency division number “6”. Set to Accordingly, the RF test signal supply circuit 18 performs frequency down-conversion from the 5802 MHz frequency to the 967 MHz frequency RF test signal, and the 967 MHz frequency RF test signal from the RF test signal supply circuit 18 is input to the low noise amplifier 4. To be supplied.

  In this case, the transmission test signal from the test signal generator 200B of the external test apparatus 200 is supplied to the input of the input amplifier 13 of the communication semiconductor integrated circuit 100. The output signal of the input amplifier 13 is supplied to the modulation control unit 14b of the FM modulator 14, whereby the output frequency of the transmission voltage controlled oscillator 14a is modulated by the output signal of the modulation control unit 14b. An RF transmission test signal having a frequency of 5802 MHz of the FM modulator 14 is amplified by the driver 15 and then supplied to the input of the RF power amplifier 16. By supplying the RF transmission test signal having a frequency of 5802 MHz of the RF power amplifier 16 to the input of the RF test signal supply circuit 18, the RF test signal supply circuit 18 performs frequency down-conversion with a frequency division number “6”.

  By this frequency down-conversion, a 967 MHz RF test signal close to the 900 MHz frequency band of the ISM frequency band is generated from the output of the RF test signal supply circuit 18 and supplied to the input of the low noise amplifier 4 of the communication semiconductor integrated circuit 100. The 967 MHz RF amplified signal of the low noise amplifier 4 is supplied to one input terminal of the reception mixer 6 via the band pass filter 5. A reception carrier signal having a predetermined frequency generated from the reception voltage control oscillator 7 is supplied to the other input terminal of the reception mixer 6, and an intermediate frequency signal is generated from the output of the reception mixer 6. The intermediate frequency signal is amplified by the intermediate frequency amplifier 9 via the band pass filter 8 and then supplied to the input of the FM demodulator 10. The FM demodulated output signal generated from the FM demodulator 10 is amplified by the output amplifier 12, and then supplied to the signal analyzer 200A of the external test apparatus 200. The signal analyzer 200A of the external test apparatus 200 analyzes the demodulated output signal from the output amplifier 12 of the communication semiconductor integrated circuit 100, thereby receiving the reception system (4 ... 12) and the transmission system (13 ...) of the communication semiconductor integrated circuit 100. 16) test whether or not to operate normally.

<< Operation of Communication Semiconductor Integrated Circuit as Master Unit >>
When the communication semiconductor integrated circuit 100 of FIG. 1 is used as a base unit of an analog cordless telephone, a command CMD is sent from the base unit to the command input unit 19 of the communication semiconductor integrated circuit 100 by an initialization operation such as when power is turned on. Is supplied. This command CMD is an operation mode setting command for operating the communication semiconductor integrated circuit 100 as a master unit of an analog cordless telephone. In that case, the RF reception signal in the frequency band of 5.8 GHz of the ISM frequency band transmitted from the slave unit and received by the antenna 1 is transmitted through the band-pass filter 3 to the low noise amplifier 4 of the semiconductor integrated circuit 100 for communication. Supplied to the input. The 5.8 GHz RF amplified signal of the low noise amplifier 4 is supplied to one input terminal of the reception mixer 6 via the band pass filter 5. A reception carrier signal having a predetermined frequency generated from the reception voltage control oscillator 7 is supplied to the other input terminal of the reception mixer 6, and an intermediate frequency signal is generated from the output of the reception mixer 6. This intermediate frequency signal is amplified by the intermediate frequency amplifier 9 via the band pass filter 8 and then supplied to the input of the FM demodulator 10. The FM demodulated output signal generated from the FM demodulator 10 is amplified by the output amplifier 12 and then supplied to the fixed telephone line as a transmission signal to the fixed telephone line.

  A received signal from the fixed telephone line is supplied from the fixed telephone line to the input of the input amplifier 13 of the communication semiconductor integrated circuit 100. The output signal of the input amplifier 13 is supplied to the modulation control unit 14b of the FM modulator 14, whereby the output frequency of the transmission voltage controlled oscillator 14a is modulated by the output signal of the modulation control unit 14b. The FM modulated RF signal in the 900 MHz frequency band of the ISM frequency band of the FM modulator 14 is amplified by the driver 15 and then supplied to the input of the RF power amplifier 16. The RF transmission signal of about 900 MHz from the RF power amplifier 16 is transferred to the slave unit via the band pass filter 17 and the antenna 1 of the master unit.

<Operational test of semiconductor integrated circuit for communication as parent device>
Whether or not the reception system (4... 12) and the transmission system (13... 16) of the communication semiconductor integrated circuit 100 operate normally when the communication semiconductor integrated circuit 100 is used as a base unit of an analog cordless telephone. It is necessary to carry out such a test.

  At this time, the command CMD is supplied from the external test apparatus to the command input unit 19 of the communication semiconductor integrated circuit 100 by an initialization operation such as when the power is turned on. This command CMD is a master unit test for testing whether the reception system (4... 12) and the transmission system (13... 16) of the communication semiconductor integrated circuit 100 used for the master unit operate normally. This is a command to set the operation mode.

  FIG. 3 is a diagram for explaining the operation of the RF test signal supply circuit 18 of the communication semiconductor integrated circuit 100 of FIG. 1 in response to the setting command to the parent device test operation mode. In this case, in the RF test signal supply circuit 18, the first frequency division number N of the first frequency divider 18a is set to "1", and the second frequency division number M of the second frequency divider 18f is "6". "Is set. Therefore, the RF test signal supply circuit 18 operates as a frequency multiplier having a multiplication number “6”.

  In this case, a 967 MHz RF test signal close to the 900 MHz frequency band of the ISM frequency band is generated from the RF power amplifier 16 of the communication semiconductor integrated circuit 100 and supplied to the input of the RF test signal supply circuit 18. The Therefore, a 5802 MHz RF test signal in the frequency band of 5.8 GHz of the ISM frequency band is generated from the output of the RF test signal supply circuit 18 and supplied to the input of the low noise amplifier 4 of the communication semiconductor integrated circuit 100.

  FIG. 15 is a diagram for explaining the test operation of communication semiconductor integrated circuit 100 of FIG. 1 using a command for setting to the parent device test operation mode.

  A 967 MHz RF transmission signal is generated from the RF power amplifier 16 in response to the command for setting the master unit test operation mode, and the operation mode of the RF test signal supply circuit 18 is set to the frequency multiplier operation of the multiplication number “6”. Is done. Therefore, the RF test signal supply circuit 18 performs frequency up-conversion from a frequency of 967 MHz to an RF test signal of 5802 MHz, and the RF test signal of 5802 MHz from the RF test signal supply circuit 18 is input to the low noise amplifier 4. To be supplied.

  In this case, the transmission test signal from the test signal generator 200B of the external test apparatus 200 is supplied to the input of the input amplifier 13 of the communication semiconductor integrated circuit 100. The output signal of the input amplifier 13 is supplied to the modulation control unit 14b of the FM modulator 14, whereby the output frequency of the transmission voltage controlled oscillator 14a is modulated by the output signal of the modulation control unit 14b. An RF transmission test signal having a frequency of 967 MHz of the FM modulator 14 is amplified by the driver 15 and then supplied to the input of the RF power amplifier 16. When the RF transmission test signal of 967 MHz frequency of the RF power amplifier 16 is supplied to the input of the RF test signal supply circuit 18, the RF test signal supply circuit 18 performs frequency up-conversion with a multiplication number “6”.

  By this frequency up-conversion, an RF test signal of 5802 MHz within the frequency band of 5.8 GHz of the ISM frequency band is generated from the output of the RF test signal supply circuit 18 and supplied to the input of the low noise amplifier 4 of the communication semiconductor integrated circuit 100. The The 5802 MHz RF amplified signal of the low noise amplifier 4 is supplied to one input terminal of the reception mixer 6 via the band pass filter 5. A reception carrier signal having a predetermined frequency generated from the reception voltage control oscillator 7 is supplied to the other input terminal of the reception mixer 6, and an intermediate frequency signal is generated from the output of the reception mixer 6. The intermediate frequency signal is amplified by the intermediate frequency amplifier 9 via the band pass filter 8 and then supplied to the input of the FM demodulator 10. The FM demodulated output signal generated from the FM demodulator 10 is amplified by the output amplifier 12, and then supplied to the signal analyzer 200A of the external test apparatus 200. The signal analyzer 200A of the external test apparatus 200 analyzes the demodulated output signal from the output amplifier 12 of the communication semiconductor integrated circuit 100, thereby receiving the reception system (4 ... 12) and the transmission system (13 ...) of the communication semiconductor integrated circuit 100. 16) test whether or not to operate normally.

<Configuration of communication semiconductor integrated circuit usable for digital cordless telephone>
FIG. 4 is a diagram showing a communication semiconductor integrated circuit 200 according to another embodiment of the present invention. This semiconductor integrated circuit for communication 200 can be used in common for the handset and base unit of the digital cordless telephone.

  The communication semiconductor integrated circuit 200 shown in FIG. 4 receives an RF signal in any one of four frequency bands of 900 MHz, 1.8 GHz, 2.4 GHz, and 5.8 GHz of the ISM frequency band. Further, the communication semiconductor integrated circuit 200 can transmit an RF signal in any one of four frequency bands of 900 MHz, 1.8 GHz, 2.4 GHz, and 5.8 GHz of the ISM frequency band.

  In the digital cordless telephone using the semiconductor integrated circuit 200 for communication, the handset has four frequency bands of 900 MHz, 1.8 GHz, 2.4 GHz, and 5.8 GHz of the ISM frequency band from the base unit connected to the fixed telephone line. An RF signal in any one frequency band is received. The slave unit transmits an RF signal in any one of the four frequency bands to the master unit. The master unit receives the RF signal in the frequency band of 5.8 GHz, and transmits the RF signal in the frequency band of 900 MHz to the slave unit. A communication semiconductor integrated circuit that can be used in common with the slave unit and the master unit can be set for the slave unit and the master unit by setting an operation mode when the power is turned on. The slave semiconductor communication integrated circuit performs, for example, 900 MHz RF signal reception and 5.8 GHz RF signal transmission. The master communication semiconductor integrated circuit, for example, receives 5.8 GHz RF signal reception and 900 MHz RF signal transmission. And do.

  When the communication semiconductor integrated circuit 200 of FIG. 4 is used for either a slave unit or a master unit of a digital cordless telephone, an antenna switch 2 is connected to the antenna 1. The antenna switch 2 supplies an RF reception input signal from the antenna 1 to the low noise amplifier 4 of the reception system, and supplies an RF transmission output signal from the RF power amplifier 16 of the transmission system to the antenna 1. The antenna switch 2 supplies an RF reception input signal and an RF transmission output signal by a time-division multiple access (TDMA) method.

  Compared with the communication semiconductor integrated circuit 100 used in the analog cordless telephone shown in FIG. 1, the configuration of the communication semiconductor integrated circuit 200 shown in FIG. 4 includes an FM modulator 14 portion and an RF test signal supply circuit 18 portion. Are different.

  First, the FM modulator 14 of the communication semiconductor integrated circuit 200 in FIG. 4 includes a mixer 14c, low-pass filters 14d and 14j, a modulation control unit 14e, a reference frequency divider 14f, a phase comparator 14g, a PLL frequency divider 14h, The credit voltage control oscillator 14i is used. The reference frequency signal Fref is supplied to the reference frequency divider 14f, and the PLL phase comparator 14g outputs the credit voltage so that the frequency of the frequency division output of the PLL frequency divider 14h matches the frequency of the output of the reference frequency divider 14f. The controlled oscillator 14i is controlled. The output signal of the input amplifier 13 is supplied to the modulation control unit 14e of the FM modulator 14, whereby the output frequency of the transmission voltage controlled oscillator 14i is modulated by the output signal of the modulation control unit 14e.

  Further, in the RF test signal supply circuit 18 of the communication semiconductor integrated circuit 200 of FIG. 4, the first frequency division number N of the first frequency divider 18a and the second frequency division number M of the second frequency divider 18f are integers. It is constituted by a fractional phase locked loop circuit that can include not only a fraction but also a fraction (a small number).

  FIG. 5 is a diagram for generating test output signals Test_Sig_Out in four frequency bands from test input signals Test_Sig_in in four frequency bands by the RF test signal supply circuit 18 configured by the fractional PLL circuit of the communication semiconductor integrated circuit 200 in FIG. It is a figure which shows the 1st frequency division number N of this and the 2nd frequency division number M. When the frequency division number of the fractional PLL circuit includes a fraction, it is possible to improve the degree of freedom when frequency-converting the test input signal Test_Sig_in in the four frequency bands into the test output signal Test_Sig_Out in the four frequency bands. The four frequency bands are 900 MHz, 1.8 GHz, 2.4 GHz, and 5.8 GHz of the ISM frequency band.

  Also, the command CMD is supplied to the command input unit 19 of the communication semiconductor integrated circuit 200 of FIG. This command CMD is an operation mode setting command for determining whether the communication semiconductor integrated circuit 200 of FIG. 4 operates in either the slave unit or the master unit of the digital cordless telephone. Further, in the command CMD, mode information indicating which of the 900 MHz, 1.8 GHz, 2.4 GHz, and 5.8 GHz frequency bands of the ISM frequency band is used by the reception system and the transmission system of the communication semiconductor integrated circuit 200. It is included.

<< RF test signal supply circuit composed of fractional PLL circuit >>
FIG. 9 is a block diagram showing an RF test signal supply circuit 18 constituted by a fractional PLL circuit in the communication semiconductor integrated circuit 200 of FIG.

  As shown in the figure, an RF test input signal Test_Sig_in in the 900 MHz frequency band of the ISM frequency band is supplied to the input of the first frequency divider 18a of the RF test signal supply circuit 18. The output signal of the first frequency divider 18a is supplied to one input terminal of the phase comparator 18b. The output of the phase comparator 18b is supplied to the voltage controlled oscillator 18e through the charge pump circuit 18c and the low pass filter 18d. The output of the voltage controlled oscillator 18e is supplied to the input of the second frequency divider 18f, and the frequency division output signal of the second frequency divider 18f is supplied to the other input terminal of the phase comparator 18b. A control input terminal for controlling the second frequency division number M of the second frequency divider 18f is connected to the frequency division ratio setting logic DRSL.

  The second frequency divider 18f is constituted by a counter, and counts up, for example, a change from low level to high level of the output of the voltage controlled oscillator 18e from zero. The frequency division output signal of the second frequency divider 18f is changed from the low level to the high level at a frequency of a value obtained by subtracting 1 from the value set at the control input terminal for controlling the second frequency division number M. When the frequency-divided output signal of the second frequency divider 18f becomes high level, the count value of the counter is set to zero by the change of the output of the next voltage controlled oscillator 18e from low level to high level. Further, the frequency division output signal of the second frequency divider 18f is returned to the low level, and the next frequency division operation is executed.

  The frequency division ratio setting logic DRSL includes a frequency division ratio calculator DRALU, a ΣΔ modulator ΣΔMod, and an adder ADD. First, the integer unit Int and the fractional unit Fra of the frequency division ratio calculator DRALU calculate integer value information I and fractional value information F based on the input information. The integer value information I from the integer unit Int of the division ratio calculator DRALU is supplied to one input terminal of the adder ADD, and the fractional value information F from the fraction unit Fra of the division ratio calculator DRALU is supplied to the ΣΔ modulator ΣΔMod. To be supplied. Further, the reference frequency signal fREF is further supplied as an operation clock signal to the ΣΔ modulator ΣΔMod. On the other hand, the ΣΔ modulator ΣΔMod holds denominator information G for setting a frequency division ratio as internal information. As an example, the denominator information G is set to 1625. The ΣΔ modulator ΣΔMod generates, from the fractional value information F and the denominator information G, an output signal F / G having fractional value information F ÷ denominator information G, for example, 715/1625 fraction information. This is supplied to the other input terminal of the adder ADD. The adder ADD sets the output information of the integer value information I (for example, I = 6) and the output signal F / G to I + F / G, for example, 6+ (715/1625) = 6.44 as the average frequency division number M. This is supplied to the second frequency divider 18f. As a result, the average frequency division number M of the second frequency divider 18f is set to a value including 6.44, an integer, and a fraction (decimal number).

  Accordingly, the RF test signal supply circuit 18 configured by a fractional PLL circuit has an oscillation frequency of 5800 MHz obtained by multiplying the RF test input signal Test_Sig_in in the 900 MHz frequency band of the ISM frequency band and the average frequency division number M (6.44). RF test output signal Test_Sig_Out is generated.

  Further, the average frequency division number M will be described in detail. The frequency according to the integer value information I (I = 6) from the integer unit Int of the frequency division ratio calculator DRALU and the output signal F / G from the ΣΔ modulator ΣΔMod. In response to the overflow and 1-bit output generated at (715/1625), the frequency division number M of the second frequency divider 18f is changed from I (= 6) to I + 1 (7). Accordingly, the frequency at which the frequency division number M of the second frequency divider 18f is I (= 6) is 910/1625 = 56%, and the frequency at which the frequency division ratio of the second frequency divider 18f is I + 1 (7) is 715/1625 = 44%. Therefore, the average frequency division ratio N is 6 × 0.56 + 7 × 0.44 = 6.44.

  FIG. 10 is a diagram showing a configuration of the ΣΔ modulator ΣΔMod in the RF test signal supply circuit 18 configured by the fractional PLL circuit shown in FIG.

  As shown in the figure, the fractional value information F from the fractional unit Fra of the frequency division ratio calculator DRALU is supplied as an input signal (A) to one input terminal of the first adder Sum1, while the first adder An output signal (C) of a second adder Sum2 described later is supplied to the other input terminal of Sum1. The output signal of the first adder Sum1 is supplied to a delay circuit as an integrator Ingtgrtr, and the output signal (B) of the integrator Ingtgrtr is supplied to the input of a quantizer qntzr having a 1-bit output. The output signal (D) of the quantizer qnttzr is supplied to the input of a feedback circuit fbc having a predetermined gain 1 / G. The reciprocal G of the gain 1 / G corresponds to denominator information G (for example, G = 1625) in which the ΣΔ modulator ΣΔMod sets a division ratio as internal information. Therefore, in the non-overflow state where the 1-bit output signal (D) of the quantizer qnttzr is “0”, the output of the feedback circuit fbc is zero, and the 1-bit output signal (D) of the quantizer qntzr is “1”. In the state, the output of the feedback circuit fbc is 1625. Therefore, the feedback circuit fbc operates as a 1-bit D / A converter. Accordingly, when an overflow state occurs in which the 1-bit output signal (D) of the quantizer qntzr is “1”, the second adder Sum2 outputs the output 1625 of the feedback circuit fbc from the cumulative addition of the output signal (B) of the integrator Ingtgrtr. Subtraction is performed. Further, the output signal (C) of the second adder Sum2 is supplied to the other input terminal of the first adder Sum1. The 1-bit output signal (D) of the quantizer qntzr indicating the non-overflow state / overflow state is supplied to the adder ADD as the output signal F / G of the ΣΔ modulator ΣΔMod.

  FIG. 11 is a diagram showing the operation of the ΣΔ modulator ΣΔMod in the RF test signal supply circuit 18 shown in FIG. The labels (A) to (D) in FIG. 11 correspond to the signals (A) to (D) in FIG.

  As shown in FIG. 9, a reference frequency signal having a reference frequency fREF is supplied to the ΣΔ modulator ΣΔMod as an operation clock signal. Further, as shown in FIG. 11A, fractional value information F is steadily supplied as an input signal (A) to one input terminal of the first adder Sum1 of the ΣΔ modulator ΣΔMod. Therefore, one cumulative addition result can be obtained from the output of the integrator Intgrtr in one cycle of the operation clock signal. As shown in FIG. 11B, the third cumulative addition result is obtained from the output signal (B) of the integrator Intgrtr in the third cycle of the operation clock signal. Further, as shown in FIG. 3D, an overflow state of “1” appears in the 1-bit output signal (D) of the quantizer qntzr in the third cycle of the operation clock signal. Then, as shown in FIG. 3C, the second adder Sum2 subtracts the output 1625 of the feedback circuit fbc from the cumulative addition of the output of the integrator Intgrtr to generate an output signal (C). . The quantizer qnttzr outputs a 1-bit output signal in a non-overflow state of “0” when the input signal is 0 to 1624, while “0” when the input signal is 1625 or larger. A 1-bit output signal in an overflow state of 1 ″ is output. The above operation is repeated in response to the operation clock signal fREF, and the 1-bit output signal in the overflow state of “1” is quantized at the frequency of the fraction information F / G (715/1625) from the ΣΔ modulator ΣΔMod. Generated from the device qntzr.

  The output signal (D) of the quantizer qntzr shown in FIG. 10, that is, the 1-bit output signal F / G of the ΣΔ modulator ΣΔMod is supplied to the adder ADD of the frequency division ratio setting logic DRSL of FIG. Is added to the integer value information I supplied from the integer unit Int of the division ratio calculator DRALU. In the non-overflow state where the 1-bit output signal of the ΣΔ modulator ΣΔMod is “0”, the frequency division number M of the second frequency divider 18 f is set to I (= 6), and the 1-bit output signal of the ΣΔ modulator ΣΔMod is “ In the overflow state of 1 ″, the frequency division number M of the second frequency divider 18f is set to I + 1 (= 7), and as a result, the average frequency division number M becomes 6.44.

<< Configuration of Other Communication Semiconductor Integrated Circuits Usable for Digital Cordless Telephone >>
FIG. 6 is a diagram showing a semiconductor integrated circuit for communication 200 according to still another embodiment of the present invention. The communication semiconductor integrated circuit 200 of FIG. 6 can also be used in common for the handset and base unit of the digital cordless telephone.

  Compared with the communication semiconductor integrated circuit 200 shown in FIG. 4, the configuration of the communication semiconductor integrated circuit 200 shown in FIG.

  In the RF test signal supply circuit 18 of the communication semiconductor integrated circuit 200 of FIG. 6, one of the input terminals of the mixer 18g has an ISM frequency band of 900 MHz, 1.8 GHz, 2.4 GHz, or 5.8 GHz. RF test input signal Test_Sig_in. The other input terminal of the mixer 18g is connected to a fractional PLL circuit including a first frequency divider 18a, a phase comparator 18b, a charge pump circuit 18c, a low-pass filter 18d, a voltage controlled oscillator 18e, and a voltage controlled oscillator 18e. Offset frequency output is provided. The reference frequency signal Fref applied to the input of the reference frequency divider 14f of the FM modulator 14 is supplied to the input terminal of the first frequency divider 18a of the fractional PLL circuit.

  FIG. 7 is a fractional diagram for generating test output signals of four frequency bands from test input signals of four frequency bands by the RF test signal supply circuit 18 configured by the fractional PLL circuit of the communication semiconductor integrated circuit 200 of FIG. It is a figure which shows the offset frequency of a PLL circuit.

  In FIG. 7, the minus sign does not indicate a negative frequency but indicates that the frequency of the test output signal Test_Sig_Out is generated by subtracting from the frequency of the test input signal Test_Sig_in. For example, when a test input signal Test_Sig_in having a frequency of 5.8 GHz and an offset frequency signal of a fractional PLL circuit having a frequency of 4.9 GHz are supplied to the mixer 18g, a 900 MHz test output signal Test_Sig_Out as a difference component is generated from the mixer 18g. When the test input signal Test_Sig_in having a frequency of 900 MHz and the offset frequency signal of the fractional PLL circuit having a frequency of 4.9 GHz are supplied to the mixer 18g, a test output signal Test_Sig_Out of a sum component of 5.8 GHz is generated from the mixer 18g.

<< Configuration of communication semiconductor integrated circuit usable for wireless LAN >>
FIG. 8 is a diagram showing a semiconductor integrated circuit 400 for communication according to still another embodiment of the present invention. The communication semiconductor integrated circuit 400 of FIG. 8 can also be used in common for a wireless LAN slave device (LAN terminal) and a master device (access point hub). An antenna switch 2 is connected to the antenna 1 and performs an RF reception input signal supply from the antenna 1 to the reception system and an RF transmission output signal supply from the transmission system to the antenna 1 by the time division multiple access method.

  8 includes a low noise amplifier 24, a reception mixer 25, programmable gain amplifiers 26 and 28, a low-pass filter 27, and an A / D converter 29. This receiving system corresponds to the frequency band of 2.4 GHz of the IEEE 802.11b standard and the frequency bands of 5 GHz and 5.8 GHz of the IEEE 802.11a standard.

  The transmission system of the communication semiconductor integrated circuit 400 includes a D / A converter 31, a low-pass filter 32, transmission mixers 33 and 34, and driver amplifiers 35 and 36. Note that RF power amplifiers 37 and 38 outside the communication semiconductor integrated circuit 400 and bandpass filters BPF4 and BPF5 are connected to the outputs of the driver amplifiers 35 and 36, respectively.

  The reception local signal supplied to the reception mixer 25 of the reception system of the communication semiconductor integrated circuit 400 and the transmission local signal supplied to the transmission mixers 33 and 34 of the transmission system are generated from the ΣΔ fractional PLL frequency synthesizer 30. The A loop filter 39 and a crystal resonator 40 are connected to the ΣΔ fractional PLL frequency synthesizer 30 outside the semiconductor integrated circuit 400 for communication.

  An RF transmission signal in the frequency band of 2.4 GHz is formed from the output of the driver amplifier 35, and an RF transmission signal in the frequency band of 5 GHz and 5.8 GHz is formed from the output of the driver amplifier 36. The first test input terminal Test_Sig_in1 and the second test input terminal Test_Sig_in2 of the RF test signal supply circuit 18 are connected to the output of the driver amplifier 35 and the output of the driver amplifier 36. The test output terminal Test_Sig_Out of the RF test signal supply circuit 18 is connected to the input of the low noise amplifier 24 of the receiving system.

  Also, the command CMD is supplied to the command input unit 19 of the communication semiconductor integrated circuit 400 of FIG. This command CMD is an operation mode setting command for determining whether the communication semiconductor integrated circuit 200 of FIG. 8 operates in either the wireless LAN slave device or the master device. The command CMD includes mode information indicating which frequency band of 2.4 GHz, 5 GHz, and 5.8 GHz is used by the reception system and the transmission system of the communication semiconductor integrated circuit 200.

  The selector 18h of the RF test signal supply circuit 18 constituted by the fractional PLL circuit of the communication semiconductor integrated circuit 400 of FIG. 8 performs the second test of the first test input signal Test_Sig_in1 output from the driver amplifier 35 and the output from the driver amplifier 36. Either one of the input signals Test_Sig_in2 is selected and supplied to the mixer 18g. In the mixer 18g, the selected test input signal and the offset frequency signal of the fractional PLL circuit are mixed, and a test output signal Test_Sig_Out of a sum component or a difference component is generated from the mixer 18g.

  Although the invention made by the present inventor has been specifically described based on the embodiments, it is needless to say that the present invention is not limited thereto and can be variously modified without departing from the gist thereof.

  For example, the RF test signal supply circuit 18 of the semiconductor integrated circuit according to the present invention is not limited to being used for a good / defective judgment test before shipment at the manufacturing stage of the semiconductor integrated circuit. For example, the RF test signal supply circuit 18 can be used to calibrate the reception error in the reception system of the semiconductor integrated circuit before the reception operation in the normal operation mode of the semiconductor integrated circuit. For example, in order to calibrate the error of various signal processing characteristics of the low noise amplifier 24, the reception mixer 25, the programmable gain amplifiers 26 and 28, and the low-pass filter 28 of the reception system of the communication semiconductor integrated circuit of FIG. An RF test signal supply circuit 18 can be used. That is, from the response characteristics of various circuits of the receiving system of the semiconductor integrated circuit for communication of FIG. 8 to the RF test output signal Test_Sig_Out that is frequency-converted by the RF test signal supply circuit 18 from the test input signal Test_Sig_in 1, 2, The characteristic can be calibrated.

  Further, a low-frequency test signal can be applied to the IC output terminal of the RF power amplifier 16 of the communication semiconductor integrated circuit 100 of FIG. This low frequency test signal is transmitted to the IC input terminal of the low noise amplifier 4 via the RF test signal supply circuit 18. A signal analyzer 200 of a low-cost general-purpose external test device analyzes the output signal of the RF test signal supply circuit 18 transmitted to the IC input terminal of the low noise amplifier 4. As a result, it is possible to test the electrical continuity between the IC output terminal of the RF power amplifier 16 of the communication semiconductor integrated circuit 100 and the IC input terminal of the low noise amplifier 4. In this case, the first frequency division number N of the first frequency divider 18a and the second frequency division number M of the second frequency divider 18f of the RF test signal supply circuit 18 are set to "1". Is done.

<< Configuration of Other Communication Semiconductor Integrated Circuits Usable for Mobile Phones >>
FIG. 12 is a block diagram showing an RF communication semiconductor integrated circuit (RF IC) 500 that can be used in a mobile phone according to still another embodiment of the present invention. This RF IC (500) can perform transmission / reception in the GSM850, GSM900, DCS1800, and PCS1900 systems of mobile phones.

  FIG. 13 is a diagram showing transmission / reception bands of various communication methods of the mobile phone. The upper part of FIG. 10 shows the transmission / reception band of the WCDMA system. In the case of GSM850, the frequency band of the RF transmission signal TX of the wireless communication terminal is 824 to 849 MHz, whereas the frequency band of the RF reception signal RX of the wireless communication terminal is 869 to 894 MHz. In the case of GSM900, the frequency band of the RF transmission signal TX of the wireless communication terminal is 880 to 915 MHz, whereas the frequency band of the RF reception signal RX of the wireless communication terminal is 925 to 960 MHz. In the case of DCS1800, the frequency band of the RF transmission signal TX of the wireless communication terminal is 1710 to 1785 MHz, whereas the frequency band of the RF reception signal RX of the wireless communication terminal is 1805 to 1880 MHz. In the case of PCS1900, the frequency band of the RF transmission signal TX of the wireless communication terminal is 1850 to 1910 MHz, whereas the frequency band of the RF reception signal RX of the wireless communication terminal is 1930 to 1990 MHz. Thus, in any frequency band (band), the FDD scheme in which the reception band frequency RX is higher than the transmission band frequency TX is adopted.

  In the test mode, the RF test signal supply circuit 18 of the RF IC shown in FIG. 12 supplies an RF test signal generated by multiplying the frequency of the RF transmission signal from the transmission circuit TX_SPU_GSM to the reception circuit RX_SPU_GSM. That is, in any of the test modes in the case of GSM850, GSM900, DCS1800, and PCS1900 of the mobile phone, the RF test signal supply circuit 18 configured by the fractional PLL can include a fraction with a frequency multiplication number as an integer. It has become. As a result, the degree of freedom of frequency conversion of the RF test signal supply circuit 18 is improved, and good tests of the mobile phones GSM850, GSM900, DCS1800, and PCS1900 are possible.

  That is, the circuit RX_SPU_GSM at the center of the RF IC shown in FIG. 12 is a circuit for receiving GSM850, GSM900, DCS1800, and PCS1900. A circuit TX_SPU_GSM below the RF IC shown in FIG. 12 is a circuit for transmission of GSM850, GSM900, DCS1800, and PCS1900.

  The circuit Frct_Synth at the center of the RF IC shown in FIG. 12 is a fractional synthesizer that forms a transmission / reception local signal of the RF IC. The fractional synthesizer Frct_Synth includes a system reference voltage controlled oscillator (DCX-CVO) 40 and a reception voltage controlled oscillator (Rx-VCO) 19.

  In any “reception mode” of any communication system of GSM850, GSM900, DCS1800, and PCS1900, the fractional synthesizer Frct_Synth at the center of the RF IC forms an appropriate reception local signal. Appropriate reception local signals are supplied to the reception mixers RX-MIX_I and RX-MIX-Q of the reception circuit RX_SPU_GSM, so that I and Q analog baseband reception signals RxABI and RxABQ are formed at the output of the reception circuit RX_SPU_GSM. This baseband signal is supplied to the baseband signal processing LSI.

  Conversely, the I and Q analog baseband transmission signals TxABI and TxABQ from the baseband signal processing LSI are converted into RF transmission signals by the transmission circuit TX_SPU_GSM. The transmission circuit TX_SPU_GSM is configured by a transmission system offset PLL circuit TX_Offset_PLL.

  The transmission system offset PLL circuit TX_Offset_PLL needs to correspond to the transmission operation of the GSM850 RF transmission signal Tx_GSM850 and the GSM900 RF transmission signal Tx_GSM900. Therefore, the oscillation frequency of the receiving Rx-VCO 19 is controlled by the phase control feedback frequency downmixer DWN_MIX_PM via the two frequency dividers DIV1 (1/2) and DIV4 (1/2) set to the frequency division ratio 2. It is supplied to one input terminal. Further, the frequency division ratio NIF of the intermediate frequency divider DIV2 (1 / NIF) connected to the transmission mixers TX-MIX_I and TX-MIX_Q is set to 26. On the other hand, the oscillation output signal of the transmission Tx-VCO 2 is supplied to the other input terminal of the phase control feedback frequency downmixer DWN_MIX_PM via the two frequency dividers DIV5 and DIV3 set to the frequency division number 2. Has been supplied to. In the downmixer DWN_MIX_PM, mixing of one input signal and the other input signal is performed. Therefore, a feedback signal having a frequency difference between the two input signals is formed from the output of the downmixer DWN_MIX_PM and supplied to the other input terminal of the phase comparator PC of the transmission system offset PLL circuit TX_Offset_PLL. Further, one input terminal of the phase comparator PC is supplied with an intermediate frequency transmission signal fIF obtained by vector synthesis of the output of the adder connected to the outputs of the transmission mixers TX-MIX_I and Q as a reference signal. The total frequency division number is 52, which is 26 as the frequency division number NIF of the intermediate frequency divider DIV2 (1 / NIF) and the frequency division number 2 at the 90-degree phase shifter. Therefore, the frequency of the intermediate frequency transmission signal fIF is 1/52 of the frequency of the reception Rx-VCO 19. Further, the negative feedback control of the transmission system offset PLL circuit TX_Offset_PLL makes the reference signal of one input terminal of the phase comparator PC coincide with the feedback signal from the downmixer DWN_MIX_PM of the other input terminal. As a result, in the transmission operation of the GSM850 of the 0.8 GHz RF transmission signal and the GSM900 of the 0.9 GHz RF transmission signal, the reception Rx-VCO 19 and the transmission Tx-VCO2 are approximately four times the transmission frequency. It oscillates from 3.6 GHz to about 3.9 GHz.

  The transmission system offset PLL circuit TX_Offset_PLL needs to correspond to the transmission operation of the RF transmission signal Tx_DCS1800 of DCS1800 and the RF transmission signal Tx_PSC1900 of PSC1900. Therefore, the oscillation frequency of the receiving Rx-VCO 19 is supplied to one input terminal of the phase control feedback frequency downmixer DWN_MIX_PM via two frequency dividers DIV1 (1/2) set to a frequency division ratio of 2. Is done. Further, the frequency division ratio NIF of the intermediate frequency divider DIV2 (1 / NIF) connected to the transmission mixers TX-MIX_I and TX-MIX_Q is set to 26. On the other hand, the oscillation output signal of the transmission Tx-VCO 2 is supplied to the other input terminal of the phase control feedback frequency downmixer DWN_MIX_PM via one frequency divider DIV5 set to the frequency division number 2. . In the downmixer DWN_MIX_PM, mixing of one input signal and the other input signal is performed. Therefore, a feedback signal having a frequency difference between the two input signals is formed from the output of the downmixer DWN_MIX_PM and supplied to the other input terminal of the phase comparator PC of the transmission system offset PLL circuit TX_Offset_PLL. Further, one input terminal of the phase comparator PC is supplied with an intermediate frequency transmission signal fIF obtained by vector synthesis of the output of the adder connected to the outputs of the transmission mixers TX-MIX_I and Q as a reference signal. The total frequency division number is 52, which is 26 as the frequency division number NIF of the intermediate frequency divider DIV2 (1 / NIF) and the frequency division number 2 at the 90-degree phase shifter. Therefore, the frequency of the intermediate frequency transmission signal fIF is 1/52 of the frequency of the reception Rx-VCO 19. Further, the negative feedback control of the transmission system offset PLL circuit TX_Offset_PLL makes the reference signal of one input terminal of the phase comparator PC coincide with the feedback signal from the downmixer DWN_MIX_PM of the other input terminal. As a result, the transmission Rx-VCO 19 and the transmission Tx-VCO2 are approximately twice the transmission frequency in the transmission operation of the DCS 1800 of the RF transmission signal of 1.7 GHz and the PCS 1900 of the RF transmission signal of 1.9 GHz. It oscillates from 3.6 GHz to about 3.9 GHz.

FIG. 1 is a diagram showing a communication semiconductor integrated circuit according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the operation of the RF test signal supply circuit of the communication semiconductor integrated circuit of FIG. 1 in response to the command for setting the slave unit test operation mode. FIG. 3 is a diagram for explaining the operation of the RF test signal supply circuit of the communication semiconductor integrated circuit of FIG. 1 in response to the command for setting to the parent device test operation mode. FIG. 4 is a diagram showing a communication semiconductor integrated circuit according to another embodiment of the present invention. FIG. 5 is a first diagram for generating test output signals of four frequency bands from test input signals of four frequency bands by an RF test signal supply circuit configured by the fractional PLL circuit of the semiconductor integrated circuit for communication of FIG. It is a figure which shows a frequency and a 2nd frequency dividing number. FIG. 6 is a diagram showing a communication semiconductor integrated circuit according to still another embodiment of the present invention. FIG. 7 shows a fractional PLL circuit for generating test output signals in four frequency bands from test input signals in four frequency bands by an RF test signal supply circuit composed of the fractional PLL circuit of the semiconductor integrated circuit for communication in FIG. It is a figure which shows the offset frequency. FIG. 8 is a diagram showing a communication semiconductor integrated circuit according to still another embodiment of the present invention. FIG. 9 is a block diagram showing an RF test signal supply circuit composed of a fractional PLL circuit in the communication semiconductor integrated circuit of FIG. FIG. 10 is a diagram showing a configuration of the ΣΔ modulator in the RF test signal supply circuit configured by the fractional PLL circuit shown in FIG. FIG. 11 is a diagram showing the operation of the ΣΔ modulator in the RF test signal supply circuit 18 shown in FIG. FIG. 12 is a block diagram showing a semiconductor integrated circuit for RF communication that can be used in a mobile phone according to still another embodiment of the present invention. FIG. 13 is a diagram showing transmission / reception bands of various communication methods of the mobile phone. FIG. 14 is a diagram for explaining a test operation of the communication semiconductor integrated circuit of FIG. 1 using a setting command to the slave unit test operation mode. FIG. 15 is a diagram for explaining the test operation of the communication semiconductor integrated circuit of FIG. 1 using the setting command to the parent device test operation mode. FIG. 16 is a diagram for explaining a test of a transmission / reception communication function as a slave unit of a semiconductor integrated circuit for communication mounted on an analog cordless telephone studied by the present inventors prior to the present invention. FIG. 17 is a diagram for explaining a test of a transmission / reception communication function as a master unit of a communication semiconductor integrated circuit mounted on an analog cordless telephone studied by the present inventors prior to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Communication semiconductor integrated circuit 1 Antenna 2 Duplexer, antenna switch 3 Band pass filter 4 Low noise amplifier 5 Band pass filter 6 Receiving mixer 7 Voltage control oscillator for reception 8 Band pass filter 9 Intermediate frequency amplifier 10 FM demodulator 11 Band pass filter 12 Output amplifier 13 Input amplifier 14 FM modulator 15 Driver 16 RF power amplifier 17 Band pass filter 18 RF test signal supply circuit

Claims (8)

A receiving system for processing an RF received input signal; and a transmitting system for generating an RF transmitted output signal;
The RF reception input signal can be set to a predetermined reception frequency band, and the RF transmission output signal can be set to a predetermined transmission frequency band different from the frequency of the reception frequency band,
An RF test signal for converting the RF transmission output signal generated in the transmission frequency band by the transmission system into an RF test signal having a frequency band that can be processed by the reception system and supplying the RF test signal to the reception system Further comprising a supply circuit;
By setting the normal operation mode, the reception system processes the RF reception input signal set in the reception frequency band, while the transmission system processes the RF transmission output signal set in the transmission frequency band. Is to generate
A semiconductor integrated circuit in which the RF test signal supply circuit supplies the RF test signal to the reception system when set in another operation mode different from the normal operation mode. The other operation mode is a test mode of the semiconductor integrated circuit,
By using the RF test signal supply circuit in the other operation mode as the test mode, it is possible to test whether the transmission system and the reception system of the semiconductor integrated circuit are normal. The semiconductor integrated circuit according to claim 1. The other operation mode is a calibration mode of the semiconductor integrated circuit,
By using the RF test signal supply circuit in the other operation mode as the calibration mode, it is possible to perform a calibration operation that reduces the reception error of the reception system of the semiconductor integrated circuit prior to the normal operation mode. The semiconductor integrated circuit according to claim 1, wherein When the frequency of the transmission frequency band of the RF transmission output signal is set higher than the frequency of the reception frequency band of the RF reception input signal, the RF test signal supply circuit is set to a frequency down-conversion mode, The RF test signal is generated by the RF test signal supply circuit by converting the RF transmission output signal to a low frequency by the function of the frequency down-conversion of the RF test signal supply circuit,
When the frequency of the transmission frequency band of the RF transmission output signal is set lower than the frequency of the reception frequency band of the RF reception input signal, the RF test signal supply circuit is set to a frequency up-conversion mode, The RF test signal is generated by the RF test signal supply circuit by converting the RF transmission output signal to a high frequency by the frequency up-conversion function of the RF test signal supply circuit. Semiconductor integrated circuit.   The semiconductor integrated circuit according to claim 4, wherein the RF test signal supply circuit includes a phase-locked loop circuit.   6. The semiconductor integrated circuit according to claim 5, wherein the RF test signal supply circuit includes a fractional phase locked loop circuit in which a frequency division number of the frequency divider can include a fraction.   The reception frequency band of the RF reception input signal and the transmission frequency band of the RF transmission output signal are any one of four frequency bands of 900 MHz, 1.8 GHz, 2.4 GHz, and 5.8 GHz of the ISM frequency band. The semiconductor integrated circuit according to claim 4, which can be set in a frequency band. Preparing the semiconductor integrated circuit according to claim 1;
In order to test an operation mode when the frequency of the transmission frequency band of the RF transmission output signal is set to be higher than the frequency of the reception frequency band of the RF reception input signal, the RF test signal supply circuit reduces the frequency. Set the conversion mode,
A reception test signal is generated from the reception system in response to a low frequency RF test signal generated by the frequency down conversion function of the RF test signal supply circuit by supplying a transmission test signal from an external test device to the transmission system. Analyzing the output signal by the external test device;
In order to test the operation mode when the frequency of the transmission frequency band of the RF transmission output signal is set lower than the frequency of the reception frequency band of the RF reception input signal, the RF test signal supply circuit increases the frequency. Set the conversion mode,
The transmission test signal from the external test device is supplied to the transmission system and generated from the reception system in response to a high frequency RF test signal generated by the frequency up-conversion function of the RF test signal supply circuit. Analyzing the received output signal by the external test device.

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