JPH0496831A - Microprocessor peripheral circuit checking device - Google Patents

Abstract

PURPOSE:To access a peripheral circuit with an actual MPU on a body to be tested by providing a connector means for connection to the actual MPU, a check device main body which accesses the peripheral circuit through the connector means, and an actual hold signal setting circuit. CONSTITUTION:A connector part 16 is put over an actual microprocessor MPU 20 of a body 18 to be tested and is connected to the actual MPU 20. At this time, the actual MPU 20 mounted on the body 18 to be tested is set to the hold state by the actual hold signal setting circuit on the side of a connector conversion board 14, and the control right is transferred to the external. Thus, the peripheral circuit is accessed from a check device main body 10 like an ICE through the connector part 16 with the actual MPU 20 on the body 18 to be tested.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for inspecting the operation of a test object incorporating an MPU (microprocessor). More specifically, the present invention relates to a microprocessor peripheral circuit testing apparatus in which an MPU of a test object is placed in a hold state while being mounted on the test object, and peripheral circuits can be accessed without removing the MPU.

[Prior Art I] In the development of devices equipped with an MPU and peripheral circuits (such as various types of memory), an ICE (in-circuit emulator) is generally used for debugging the actual device.

ICE allows debugging by inserting the probe into the IC socket of the test object where the original MP IJ is installed and controlling it with an emulation MPU of the same type as the original MPU.0 For example, from any address in the program. You can start the program, break at any point, display/modify the register contents at that time, display a trace of the program being executed, transfer data to memory, display/modify the contents, etc. Such IcE is mainly used for software debugging.

[Question B to be solved by the invention] In order to attach the ICE probe to the IC socket for debugging, it is necessary to temporarily remove the MPU from the IC socket, and after debugging, it is necessary to attach the MPU to the IC socket. be. In other words, the conventional rCE described above cannot be used unless the MPU is mounted on the test object using an IC socket.

However, the work of attaching and detaching these MPUs is complicated and requires excessive force, which may bend or break the MPLI bottle, resulting in defective MPUs. Further, the use of an IC socket is expensive in terms of cost and is not preferable from the viewpoint of improving reliability. However, in a system in which the MPU is directly attached to the board without using an IC socket, such a configuration cannot be adopted because the conventional ICE as described above cannot be used.

The purpose of the present invention is to eliminate the drawbacks of the prior art as described above, and to provide an inspection method for microprocessor peripheral circuits in which the peripheral circuits of the MPU can be accessed while the MPU is mounted on the test object, and redephasizing, etc. can be performed. It is to provide equipment.

[Means for Solving the Problems] The present invention provides a microprocessor peripheral circuit that externally supplies signals to test the operation of an MPU having a hold state setting terminal and its peripheral circuitry. It is an inspection device. In order to achieve the above object, the present invention includes:
The present invention includes a connector means for connecting to a real MPU mounted on a test object, an inspection device main body for accessing peripheral circuits through the connector means, and an actual hold signal setting circuit for setting the real MPU in a hold state. ing. This allows the actual MPU to be placed in a hold state while mounted on the device under test, allowing access to the peripheral circuits.

Here, [actual MPUJ is the MP mounted on the test object.]
It means U. The connector means may be a single connector,
It may also be a collection of multiple connectors.

The actual hold signal setting circuit may be a pull amplifier or a pull-down circuit that can activate a terminal that puts the MPLI in a hold state depending on the model of the MPU of the test object.

This device is not only a software debugger such as a conventional ICE, but also a timing generator that decodes instructions read from the peripheral circuit of the device under test and sends signals at the same timing as the actual MPU according to the instructions. It can also be applied to a hardware inspection device such as a spy processing device that uses it to perform a processing operation in a pseudo manner.

[Operation] By attaching the connector means to the actual MPLI mounted on the test object, the inspection apparatus main body and the test object are electrically connected. MP by actual hold signal setting circuit
When a signal that puts U in a hold state is supplied, the actual MPU goes into a hold state and is cut off from the peripheral circuits of the device under test.

Therefore, the test object can be accessed from the test device main body via the connector means, and various tests on the peripheral circuits can be performed. Therefore, even if the MPU is directly attached to a board or installed in an IC socket, it can be inspected as is.

Embodiment 1 and FIG. 4 show an example of a system configuration using a peripheral circuit testing device according to the present invention.

The inspection device main body 10 is connected to a host computer via a line, and performs an iv test on a connector section 16 provided below via a connector conversion board 14 attached to the tip of a cable 12 between test objects. It can be attached to the actual MPU 20 installed in the MPU 8. In other words, by attaching the connector section 16 while the actual MPU 20 is mounted on the board, the corresponding signal lines are interconnected.

In addition to the actual MPU 20, the test object 18 includes peripheral circuits (
For example, a circuit including a program-loaded EFROM 22, RAM 24, etc.) is mounted.

The inspection device main body 10 may be, for example, a conventional ICE main body. In that case, the software will be debugged as described above based on instructions from the host computer.

The MPU to which the present invention can be applied is of a type that has a terminal for setting the hold state, and in this example, the package structure is PLCC and the model number is 80286 (manufactured by Intel Corporation).
This is a case where a 16-bint MPU known as . This test object 18 receives the MPU's actual hold state request signal ()IOL[] signal) and actual hold state response signal (HL
IIA signal) is used. An example of the circuit is shown in FIG.

The actual hold state request signal '4g30 and the actual hold state response signal line 32 of the test object 18 are short-circuited in advance.
Jumper terminals 34 and 36 that can be opened are provided.

Connector 3 to those jumper terminals 34 and 36 respectively.
8.40 is removable (see Figure 1) Connector 3
A connector conversion board 14 is connected to the MPU side of 8 via a cable 42, and an actual hold signal setting circuit 44 provided thereon is connected. The actual hold signal setting circuit 44 is composed of a +5V line and a pull-up resistor R connected thereto. The cable 4 is connected from the connector conversion board 14 to the peripheral circuit side of the other connector 40.
An actual hold condition response signal is provided via 6.

In normal operation, the jumper terminals 34 and 36 of the actual hold state request signal line 30 and the actual hold state response signal line 32 are shorted. When inspecting the connection of ICE, etc., please refer to Figures 1 and 2.
As shown in the figure, the jumper terminals 34.36 of the actual hold state request signal line 30 and the actual hold state response signal line 32 are opened and the connectors 38.40 are connected. The connector portion 16 is connected to the actual MPU 20 of the test object 18 by being placed over the actual MPU 20 from above. At this time, the test object 20
The 110LD input terminal of the actual MPU 20 is set to rH by the actual halt signal setting circuit 44 of the connector conversion board 14.
Become J level. As a result, the real MPU 20 mounted on the test object 18 enters a hold state and hands over control authority to the outside. The address bus and data bus are in a high impedance floating state. Therefore, while the real MPU 20 is mounted on the test object 18, it is possible to access the peripheral circuits from the inspection apparatus main body 10 such as an ICE via the lid 6.

Note that the connector conversion board 14 is provided so that it can be used with multiple types of MPUs (including those with different puff cage structures) by simply replacing the connector section 16, and is not indispensable. The actual hold signal setting circuit 44 may be provided on the inspection device main body 10 side.

FIG. 3 shows another example of application of the present invention.

This is an example where the actual hold state request signal (HOLD signal) and the actual hold state response signal (ILDA signal) are not used. Under normal conditions, the actual MPU2 of the test object
The HOLD input terminal of 0 is connected to r by pull-down resistor R7.
It is dropped to the LJ level and the real MPU is "active". In this case, a real hold signal setting circuit 44 consisting of a +5V line, a puller, and a 7-piece grinding resistor R1 is provided on the connector conversion board side, and the real hold setting circuit 44 (“H If the configuration is configured to supply a ``level signal'', the actual MPU can be placed in a hold state only during scanning. In other words, it is not necessarily necessary to provide a jumper terminal or the like for opening and shorting the actual hold state request signal line and the actual hold state response signal line.

When the HOLD input terminal reaches the rHJ level, the real MPU becomes disconnected from the peripheral circuits (high impedance state a) as described above, and even if a signal is directly applied to the real MPU terminal from the test equipment main body, the real MPU There will be no hindrance.

The present invention can be applied as long as the MPU of the device under test has a terminal for setting a hold state.

For example, an MPU known as the 68000 series (Motorola Corporation) has an input terminal called HALT ()IALT), and by operating this input terminal, the actual MP
You can put U into a hold state. Also, the package structure is PL.
It is not limited to CC type.

[Effects of the Invention] As described above, the present invention has the following advantages:
A microprocessor peripheral circuit testing device comprising a connector for connecting to a PU, a testing device main body for accessing peripheral circuits via the connector, and a real hold signal setting circuit for putting the real MPU in a hold state. Because of this, M
The peripheral circuits of the PU can be accessed and debugging etc. can be performed. Therefore, there is no need to remove or attach the MPU from the RC socket, and it is possible to prevent damage to the bottle and the occurrence of defects in the expensive MPU. Furthermore, since an IC socket is not required for inspection, manufacturing costs can be reduced and reliability can be improved.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of an inspection system to which the present invention is applied seen from the side, Fig. 2 is a circuit diagram of its main parts, Fig. 3 is a circuit diagram of main parts in another application example, and Fig. 4 is a diagram of the present invention. 1 is an overall configuration diagram of an inspection system to which the invention is applied. 1001. Inspection device main body, 12... Cable between test objects, 14... Connector conversion board, 16... Connector section, 18... Test object, 20... Actual MPU, 44
...Actual hold signal setting circuit. Patent applicant: Iwaki Denshi Co., Ltd. Agent: Minoru Shigeru Figure 3 + 5VI44 Figure 2

Claims (1)

[Claims] 1. Connect to the actual MPU mounted on the DUT in a device that supplies signals from the outside and tests the operation of the DUT, which is equipped with an MPU and its peripheral circuits that have terminals for setting the hold state. A test device body for accessing peripheral circuits through the connector means, and an actual hold signal setting circuit for setting the real MPU in a hold state, and holding the real MPU while it is mounted on the test object. A microprocessor peripheral circuit inspection device that enables peripheral circuits to be accessed.