CN111835631A

CN111835631A - Hot plug detection system and detection method for intelligent gateway expansion board

Info

Publication number: CN111835631A
Application number: CN202010797576.0A
Authority: CN
Inventors: 董永; 张超; 刘济瑀
Original assignee: Datang Semiconductor Technology Co ltd; Beijing Institute of Architectural Design Group Co Ltd
Current assignee: Datang Semiconductor Technology Co ltd; Beijing Institute of Architectural Design Group Co Ltd
Priority date: 2020-08-10
Filing date: 2020-08-10
Publication date: 2020-10-27

Abstract

The invention discloses a hot plug detection system and a detection method for an intelligent gateway expansion board, wherein the system comprises an expansion board connector, a function expansion board and a main control chip; the detection pin PRSNT1# at one end of the extension board connector is electrically connected with the GPIO2 pin and the ADC pin of the main control chip respectively, and the GPIO2 pin and the ADC pin of the main control chip are also connected with the ADC pin through a resistor R₁The detection pin PRSNT2# at the other end of the extension board connector is electrically connected with the GPIO1 pin of the main control chip, and the GPIO1 pin of the main control chip is also connected with the ground through a pull-up resistor R₃Is electrically connected with an interface power supply; two gold fingers corresponding to the detection pin PRSNT1# and the detection pin PRSNT2# on the function expansion board pass through a resistor R₂And (6) electrically connecting. The system enhances the reliability of hot plug detection, realizes the hot plug detection of the function expansion board and prevents the standard PCIE cardThe function is inserted by mistake, the type of the function expansion board can be judged under the condition that the function expansion board is not electrified, the detection process is simpler, more convenient, more accurate and more reliable, and the function is more perfect.

Description

Hot plug detection system and detection method for intelligent gateway expansion board

Technical Field

The invention relates to the technical field of plug-in card detection and identification, in particular to a hot plug detection system and a hot plug detection method for an expansion board of an intelligent gateway.

Background

At present, when the intelligent gateway needs resource upgrade and function expansion, an expansion board needs to be inserted, the expansion board usually needs to be connected with the gateway body by means of a standard PCIE X1 slot, and except three pins, namely GND, PRSNT1#, and PRSNT2#, interface signals of the other pins are generally self-defined. As shown in fig. 1, a pin PRSNT1# on a motherboard is grounded, a pin PRSNT2# is connected to an interface power supply through a resistor, a gold finger on a PCI Express card is contacted with a corresponding pin on the motherboard when the PCI Express card hot plug detection circuit is used, and the insertion state and validity of the PCI Express card are judged through a hot plug control logic.

The hot plug scheme of the existing intelligent gateway expansion board is based on the above standard PCIE hot plug detection circuit, and the hot plug detection principle based on the hot plug detection circuit is as follows: when no card is inserted, the hot plug detection signal is at a high level; and after the function expansion card is inserted, the hot plug detection signal is at a low level. The main control chip judges the insertion and extraction state of the function expansion card by detecting the level change of the hot plug detection signal, and then performs subsequent control.

The existing hot plug detection circuit for the intelligent gateway extension board is specifically shown in fig. 2, a PRSNT2# pin on the intelligent gateway extension board connector is connected with a GPIO pin of a main control chip for transmitting a hot plug detection signal, and the GPIO pin of the main control chip is further connected with a pull-up resistor. Meanwhile, the pin of the PRSNT1# on the main board side is suspended, and the gold finger of the card side corresponding to the PRSNT2# is directly grounded. The advantage of this is that it can be ensured that when a standard PCIE card is erroneously inserted into an intelligent gateway expansion slot, it is not recognized by the gateway expansion board connector (the gateway expansion board connector cannot recognize that a card is inserted). However, the scheme also has the following defects:

1. since only the pin PRSNT2# on the PCIE X1 slot side is used for plug/unplug detection, it cannot be ensured whether the pin PRSNT1# is completely inserted. Therefore, the effect of plugging and unplugging detection is inevitably affected (this is also the reason why the detection pins are arranged on the two sides of the slot in the PCIE standard).

2. The function expansion cards corresponding to the intelligent gateway expansion board are divided into different types according to the communication interface types. The current hot plug design can only ensure the detection of the plug of the function expansion card, and the type of the function expansion card can only be identified by software after power-on, thereby realizing more complex realization.

Therefore, how to provide a hot plug detection scheme for an intelligent gateway expansion board with higher detection reliability and more complete functions is a problem that needs to be solved urgently by technical personnel in the field.

Disclosure of Invention

In view of the above, the present invention provides a hot plug detection system and a detection method for an intelligent gateway expansion board, where the system uses two detection pins PRSNT1# and PRSNT2# at two ends of an expansion board connector to enhance the reliability of hot plug detection, and through the internal arrangement of the system, the type identification of a function expansion card can be realized without powering on the function expansion board besides the hot plug function, so as to solve the problems of low reliability and complicated type identification process of the existing hot plug detection scheme.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a hot plug detection system for an expansion board of an intelligent gateway, comprising: the system comprises an expansion board connector, a function expansion board and a main control chip;

the detection pin PRSNT1# at one end of the extension board connector is electrically connected with the GPIO2 pin and the ADC pin of the main control chip respectively, and the GPIO2 pin and the ADC pin of the main control chip are also connected with each other through a resistor R₁The detection pin PRSNT2# at the other end of the extension board connector is electrically connected with the GPIO1 pin of the main control chip, and the GPIO1 pin of the main control chip is also connected with the ground through a pull-up resistor R₃Is electrically connected with an interface power supply;

two gold fingers on the function expansion board corresponding to the detection pin PRSNT1# and the detection pin PRSNT2# pass through a resistor R₂Electric connectionAnd different types of the function expansion board internal resistance R₂Are different.

The invention has the beneficial effects that: the system uses two detection pins PRSNT1# and PRSNT2# at two ends of an expansion board connector to enhance the reliability of hot plug detection, the two detection pins PRSNT1# and PRSNT2# are respectively connected to a GPIO2 pin and a GPIO1 pin of a main control chip, through interaction between the two GPIO pins, the hot plug detection of a function expansion board and the detection function of preventing a standard PCIE card from being inserted mistakenly are realized, meanwhile, the detection pin PRSNT1# on the expansion board connector is also connected with an ADC pin of the main control chip, and in the function expansion board, a series resistor R is connected between gold fingers at two ends₂After the function expansion card is inserted and detected, the different types of function expansion cards are connected with the resistor R in series₂The resistance values are different, the voltage values detected by the ADC pins are also different, through the voltage values, the type of the function expansion board can be judged by the main control chip under the condition that the function expansion board is not electrified, and corresponding configuration is directly carried out.

Further, the resistor R₃Is greater than or equal to the resistance R₂10 times the resistance value of (a). To ensure that the GPIO1 pin can be based on a pull-up resistor R₃And a resistor R connected in series in the function expansion card₂The switching-in state of the GPIO1 pin is obviously distinguished from the input voltage, so that the high-low state of the input level is accurately judged by a pull-up resistor R₃Is much larger than the resistance R₂The resistance value of (c).

Further, the GPIO2 pin of the main control chip is also connected with a pull-down resistor R₄And (6) electrically connecting. Pull-down resistor R₄One device is not necessarily provided. Only has the resistor R₄Can be at R₁Under the condition of fixed resistance value, give R₄And the resistance value selection range is wider, so that more types of function expansion cards can be conveniently adapted and distinguished.

Further, the resistor R₁、R₂And R₄There is the following relationship between:

in the formula, V_ilmaxIndicating the maximum voltage value, V, of the input low level of the corresponding pin of the main control chip_ioRepresenting the IO supply voltage value of the pin.

The resistance relationship in the above formula is mainly defined to ensure that the GPIO2 pin input is low when the function expansion board is inserted. And then can more accurate realization whether the card that inserts is the function expansion card at present, prevent that standard PCIE card from inserting by mistake.

On the other hand, the invention also provides a hot plug detection method for the intelligent gateway expansion board, and the method uses the hot plug detection system for the intelligent gateway expansion board, and comprises the following steps:

card insertion detection: presetting a GPIO1 pin of the main control chip as input low level interruption, configuring a GPIO2 pin as output low level, setting an ADC pin to be disabled, and judging whether a card is inserted into the expansion board connector according to the input level state of the GPIO1 pin;

and (3) misplug detection: when the card is judged to be inserted into the expansion board connector, setting a GPIO2 pin as an input, configuring a GPIO1 pin to output a high level, and judging whether the card inserted into the expansion board connector is a function expansion board or not according to the level state input by the GPIO2 pin;

and (3) type detection: when the card inserted into the expansion board connector is judged to be a function expansion board, enabling the ADC pin, measuring the voltage of the detection pin PRSNT1#, inquiring the model of the corresponding function expansion board from a preset voltage value and board card model correspondence table according to the voltage of the detection pin PRSNT1#, supplying power to the expansion board connector after inquiring the model of the corresponding function expansion board, and configuring the function expansion board;

card pulling detection: configuring the GPIO1 pin as an input high-level interrupt, configuring the GPIO2 pin as an output low-level, closing an ADC pin, and judging whether the function expansion board is pulled out or not according to the level state of the GPIO1 pin;

and (3) state recovery: and after the function expansion board is pulled out, the expansion board connector is powered off and is restored to the configuration state of the pins in the step of detecting the plug-in card.

Further, when the GPIO2 pin of the main control chip and the pull-down resistor R₄When the plug is electrically connected, in the step of misplug detection, after the GPIO2 pin is set as input, a pull-down resistor R is also set₄And enabling.

Further, in the step of detecting the insertion of the card, whether the card is inserted into the expansion board connector is determined according to the input level state of the GPIO1 pin, which specifically includes:

when the input of the GPIO1 pin is high level, it is determined that no card is inserted;

when the input to the GPIO1 pin is low, an interrupt is generated to determine that a card is inserted.

Further, in the step of detecting the misplug, judging whether the card inserted into the expansion board connector is a function expansion board according to the level state input by the GPIO2 pin, specifically including:

when the input of the GPIO2 pin is at a high level, judging that the card inserted into the expansion board connector is a standard PCIE card;

and when the input of the GPIO2 pin is in a low level, judging that the card inserted into the expansion board connector is a function expansion board.

Further, in the card pulling detection step, whether the function expansion board is pulled out is judged according to the level state of the GPIO1 pin, which specifically includes:

when the input of the GPIO1 pin is at a low level, judging that the function expansion board is not pulled out;

when the input of the GPIO1 pin is high level, an interrupt is generated, and the function expansion board is judged to be pulled out.

The detection method provided by the invention can distinguish the function expansion board from the standard PCIE card while realizing hot plug detection, thereby preventing the occurrence of wrong card insertion, and meanwhile, the method can also identify the type of the function expansion board under the condition that the function expansion board is not electrified, thereby improving the efficiency and the accuracy of hot plug and type detection of the function expansion board.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic diagram of a conventional hot plug detection circuit for a standard PCI Express card;

fig. 2 is a schematic structural diagram of a conventional hot plug detection system for an intelligent gateway expansion board;

fig. 3 is a schematic structural diagram of an intelligent gateway expansion board hot plug detection system according to the present invention;

fig. 4 is a schematic flow chart of a hot plug detection method for an intelligent gateway expansion board according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

On one hand, referring to fig. 3, an embodiment of the present invention discloses an intelligent gateway expansion board hot plug detection system, including: the expansion board connector 2, the function expansion board 1 and the main control chip 3;

the detection pin PRSNT1# at one end of the extension board connector 2 is electrically connected with the GPIO2 pin and the ADC pin of the main control chip 3 respectively, and the GPIO2 pin and the ADC pin of the main control chip 3 are also connected with a resistor R₁The detection pin PRSNT2# at the other end of the extension board connector 2 is electrically connected with the GPIO1 pin of the main control chip 3, and the GPIO1 pin of the main control chip 3 is also connected with the ground through the upper pinPulling resistance R₃Is electrically connected with an interface power supply;

two gold fingers corresponding to the detection pin PRSNT1# and the detection pin PRSNT2# on the function expansion board 1 pass through a resistor R₂Electrical connection, different types of internal resistance R of the function expansion board 1₂Are different.

In particular, the resistance R₃Is at least the resistance R₂10 times the resistance value of (a). To ensure that the GPIO1 pin can be based on a pull-up resistor R₃And a resistor R connected in series in the function expansion card₂The switching-in state of the GPIO1 pin is obviously distinguished from the input voltage, so that the high-low state of the input level is accurately judged by a pull-up resistor R₃Is much larger than the resistance R₂The resistance value of (c).

Specifically, the GPIO2 pin of the main control chip 3 is also connected to a pull-down resistor R₄And (6) electrically connecting. Pull-down resistor R₄One device is not necessarily provided. Only has the resistor R₄Can be at R₁Under the condition of fixed resistance value, give R₄And the resistance value selection range is wider, so that more types of function expansion cards can be conveniently adapted and distinguished.

Specifically, in order to ensure that the GPIO2 pin input is low when the function expansion board 1 is inserted. And then can more accurate realization whether the card that inserts at present is the judgement of function extension card, resistance R₁、R₂And R₄The following relationship needs to be satisfied:

On the other hand, referring to fig. 4, an embodiment of the present invention further discloses a method for detecting hot plug of an intelligent gateway expansion board, where the method uses the above-mentioned system for detecting hot plug of an intelligent gateway expansion board, and includes:

card insertion detection: presetting a GPIO1 pin of a main control chip as input low level interruption, configuring a GPIO2 pin as output low level, setting an ADC pin to be disabled, and judging whether a card is inserted into the expansion board connector according to the input level state of the GPIO1 pin;

in a card-to-be-inserted state, a GPIO1 pin is set to be input and interrupted by a falling edge (low level); the GPIO2 pin is configured to output a low level; the ADC pin is not enabled. Because of the pull-up resistor R₃Is much larger than the resistance R₂The resistance value of GPIO1 pin input is high when no card is inserted; once a card is inserted, the GPIO1 pin input goes low, and an interrupt is generated to notify the main control chip.

For example: r₃1M Ω, R in a standard function expansion card₂100K Ω. Then the GPIO1 pin input voltage is V_io11, i.e. 0.09V_ioThe low level can be accurately judged and the interrupt is triggered.

And (3) misplug detection: when the card is judged to be inserted into the expansion board connector, setting the GPIO2 pin as input, configuring the GPIO1 pin to output high level, and judging whether the card inserted into the expansion board connector is a function expansion board or not according to the level state input by the GPIO2 pin;

when the main control chip judges that a card is inserted, the GPIO2 pin is configured as input, and the internal pull-down resistor R₄Enabling; the GPIO1 pin is then configured to output a high level. Detecting the state of a standard PCIE card, determining whether the standard PCIE card is the standard PCIE card, specifically, if the standard PCIE card is inserted, because the detection pin PRSNT1# and the detection pin PRSNT2# correspond to the card side golden finger which is directly short-circuited, the pin input of the GPIO2 is high level V_io. If the function expansion board matched with the intelligent gateway is inserted, the series resistance R between the detection pin PRSNT1# and the card side golden finger corresponding to the detection pin PRSNT2#, is detected₂. The GPIO2 pin input voltage is:

by appropriate selection of R₁、R₂Due to the maximum voltage V of the main control chip in the intelligent gateway_ilmax＝0.3V_ioTherefore, it is required to

When applied to other platforms, according to V_ilmaxThe value range can vary. Through the resistance value setting, the GPIO2 pin input can be ensured to be at a low level. Thus, whether the inserted PCIE card is a standard PCIE card can be judged. If the PCIE card is the standard PCIE card, the power is not supplied to the card, and the abnormity is reported.

For example: some standard function expansion board R₂When 100K Ω, 47K Ω, and 33K Ω, R4 and R1 are used, the input voltage of the GPIO2 pin is:

due to 0.1624V_ioV smaller than chip_ilmax(0.3V_io) The input may be judged to be low, and it is confirmed that the card is a recognizable standard function expansion card. If the card is a standard PCIE card, the input voltage of the GPIO2 pin is V_ioAnd is high.

And (3) type detection: when the card inserted into the expansion board connector is judged to be a function expansion board, enabling an ADC pin, measuring the voltage of a detection pin PRSNT1#, inquiring the model of the corresponding function expansion board from a preset voltage value and board card model correspondence table according to the voltage of the detection pin PRSNT1#, supplying power to the expansion board connector after inquiring the model of the corresponding function expansion board, and configuring the function expansion board;

after the main control chip judges that the inserted function expansion board matched with the intelligent gateway enters a function expansion card type detection state, the GPIO2 pin is changed into a pin without internal pull-down, an ADC pin is enabled, the voltage of a detection pin PRSNT1# is measured, and the calculation formula of the voltage is as follows:

then, the main control chip queries a preset 'voltage value-board card model' corresponding table in the system according to the read voltage value, and can judge what type of function expansion board is, and supply power and configure the function expansion board. If the voltage value does not conform to any type in the table at this stage, the function expansion board in the system is judged not to be, the power is not supplied to the function expansion board, and meanwhile, the abnormity is reported. The structure of the voltage value-board model correspondence table is substantially as shown in the following table 1:

TABLE 1 Voltage value-Board card model number correspondence table

Card type	GPIO2 pin voltage value	Parameter 1: supply voltage	Parameter	2
					1#	0.24V_io～0.26V_io	3.3V	…
2#	0.17V_io～0.19V_io	5V	…
				3#	…	…	…
…	…	…	…

For example: standard function expansion board 1# inner R₂100K Ω, R in standard function expansion board # 2₂150K Ω. At this stage, the input voltage of the GPIO2 pin when the 1# card is inserted is:

the input voltage of the GPIO2 pin when the 2# card is inserted is as follows:

and then the main control chip inquires a preset voltage value-board model corresponding table in the system according to the read voltage value, and the two inserted boards can be identified to be 1# and 2# respectively.

Card pulling detection: configuring a GPIO1 pin as an input high level interrupt, configuring a GPIO2 pin as an output low level, closing an ADC pin, and judging whether the function expansion board is pulled out or not according to the level state of the GPIO1 pin;

after the function expansion card is normally configured, the function expansion card enters a state to be pulled out, and a GPIO1 pin is configured to be input and interrupted in a rising edge (high level); the GPIO2 pin is configured to output low, turning off the ADC pin. The system waits for the function expansion card to be pulled out and interrupted.

And (3) state recovery: after the function expansion board is pulled out, the expansion board connector is powered off, and the configuration state of the pins in the step of detecting the plug-in card is recovered.

When the GPIO1 pin detects a high-level interrupt, the function expansion card is proved to be pulled out. The mainboard cuts off the power of the expansion board connector and restores the related detection circuit of the intelligent gateway expansion board to the state of the card to be inserted.

The above process can be visualized by the following table 2:

TABLE 2 Hot-swap status recording Table

In the present embodiment, the pull-down resistor R₄And is not required. Only having pull-down resistor R₄Can be at the resistance R₁Under the condition of fixed resistance value, the pull-down resistor R is supplied₄And the resistance value selection range is wider, so that the function expansion cards of more types can be conveniently distinguished.

In addition, the GPIO function and the ADC function in part of the main control chip can be multiplexed on the same pin, so that the GPIO2 function and the ADC function can be switched through software.

In summary, compared with the prior art, the hot plug detection scheme for the intelligent gateway function expansion board disclosed by the embodiment of the invention has the following advantages:

1. the system uses two detection pins PRSNT1# and PRSNT2# at two ends of an expansion board connector to enhance the reliability of hot plug detection;

2. two detection pins PRSNT1# and PRSNT2# of the expansion board connector are respectively connected to a GPIO2 pin and a GPIO1 pin of the main control chip (wherein the GPIO2 pin is internally provided with a matched pull-down resistor). The hot plug detection of the function expansion board and the function of preventing the false detection of a standard PCIE card are realized through the interaction between the two GPIO pins;

3. the detection signal of the detection pin PRSNT1# at one end of the expansion board connector is simultaneously accessed to one ADC input pin of the main control chip. In the function expansion board, a series resistor R is connected between two detection pins₂. After the function expansion board is inserted and detected, the ADC pin on the main control chip, the two GPIO pins for detection and the pull-down resistor R of the main control chip₁And a series resistor R on the function expansion card₂Thus, a voltage detection circuit is formed. Due to different types of function expansion in-board series resistors R₂The voltage values detected by the ADC pins are different. Through the voltage value, the main control chip can judge that the function expansion board is not electrifiedThe type of the function expansion board directly performs corresponding configuration, and the detection efficiency and accuracy are improved.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The utility model provides an intelligent gateway expansion board hot plug detecting system which characterized in that includes: the system comprises an expansion board connector, a function expansion board and a main control chip;

two gold fingers on the function expansion board corresponding to the detection pin PRSNT1# and the detection pin PRSNT2# pass through a resistor R₂And (6) electrically connecting.

2. The hot plug detection system for the expansion board of the intelligent gateway as claimed in claim 1, wherein the resistor R is a resistor R₃Is large in resistance valueIs equal to or higher than the resistance R₂10 times the resistance value of (a).

3. The hot plug detection system of claim 1, wherein the GPIO2 pin of the main control chip is further connected with a pull-down resistor R₄And (6) electrically connecting.

4. The hot plug detection system for an intelligent gateway expansion board according to claim 3, wherein the resistor R is connected to the hot plug detection system₁、R₂And R₄There is the following relationship between:

5. An intelligent gateway expansion board hot plug detection method, which uses the intelligent gateway expansion board hot plug detection system according to any one of claims 1-4, and comprises:

6. The hot plug detection method for the expansion board of the intelligent gateway as claimed in claim 5, wherein when the GPIO2 pin of the main control chip and the pull-down resistor R are connected₄When the plug is electrically connected, in the step of misplug detection, after the GPIO2 pin is set as input, a pull-down resistor R is also set₄And enabling.

7. The method according to claim 5, wherein in the plug-in card detection step, whether a card is inserted into the expansion board connector is determined according to an input level state of a GPIO1 pin, and the method specifically comprises:

8. The hot plug detection method of the intelligent gateway expansion board according to claim 5, wherein in the step of false plug detection, whether the card inserted into the expansion board connector is a function expansion board is judged according to the level state input by a pin GPIO2, which specifically includes:

9. The hot plug detection method for the intelligent gateway expansion board according to claim 5, wherein in the card pulling detection step, whether the function expansion board is pulled out is judged according to a level state of the GPIO1 pin, and specifically the method comprises: