JPH01286009A - Diagnosing system for interface control circuit - Google Patents

Abstract

PURPOSE:To diagnose an action with a simple constitution by sending an initializing signal or a response prohibiting signal during the diagnosing action execution and forcibly executing the action stoppage or the response prohibition of other device. CONSTITUTION:An interface control circuit 1 is the one to give and receive data between common buses, becomes a diagnosing object and is composed of a driver 3, a receiver 4, etc. A test mode latch 22 is set when the action diagnosis of the interface control circuit 1 is performed, a system resetting signal is sent to the common buses by setting, other all devices are held in the initializing condition. Address output input latches 5 and 6, a master control circuit 7-1, a slave control circuit 7-2, an address setting register 7-3, etc., are provided. Thus, during the holding or the response prohibition at the initializing condition of other device, a control signal, data and an address are sent to the common buses from the driver 3 and these are latched through the receiver 4 and an action diagnosis is performed.

Description

[Detailed Description of the Invention] [Summary] The present invention is a diagnostic method that verifies the validity of an interface control circuit by looping back signals of a common bus inside hardware, in which the influence of diagnostic operations on connected devices is reduced. In order to solve the problem of increasing the amount of material and increasing the number of points that cannot be diagnosed by folding back the signal internally to prevent Send a signal or send a no-response signal to a dedicated test line,
By forcibly stopping the operation of other connected devices or prohibiting them from responding, this system suppresses the increase in volume due to internal loopbacks and makes it possible to diagnose using actually operating hardware.

(Industrial Application Field) The present invention relates to a diagnostic method for diagnosing an interface control circuit connected to a common bus.In particular, the present invention relates to a diagnostic method for diagnosing an interface control circuit connected to a common bus. This invention relates to verifying the validity of a common bus interface in a computer system that performs coupling using a common bus.

[Conventional technology]

Conventionally, verification of the bus interface control circuit of a computer system connected by a common bus has been carried out in order to diagnose its operation without affecting other devices connected to the common bus, as shown in Figure 3. , the so-called folding method is used. This loopback method uses a MUX to loop back and incorporate control signals (strobe signals, response signals, etc.), address signals, and data sent to the common bus within the interface IIJ control circuit 21.
(Multiplexer) or MUX4 was installed. The operation will be briefly explained below.

In FIG. 3, the test mode latch 22 is set and MUXI to MUX4 are switched to the A side. For example, a control signal (such as a strobe signal) to be sent from the mask control circuit to the common bus is taken into the slave control circuit via MUX4. Similarly,
MUX2 and MUX output the data and address to be sent from the data output latch and address output latch to the common bus.
The data is taken into the data input latch and address input latch via l. Based on these captured control signals, data, and addresses, the operation of the interface control circuit 21 is diagnosed.

[Problem that the invention seeks to solve]

The conventional interface control circuit 21 shown in FIG. 3 uses a MUX to return control signals internally for diagnosis.
1 or MUX4, there was a problem in that the amount of material increased.

In addition, since control signals and the like were looped back internally under conditions that did not affect the common bus, the driver DVI or DV that sends control signals to the common bus
4 and the receivers RVI to RV4, which receive control signals and the like from the common bus, cannot be diagnosed.

The present invention sends an initialization signal defined in the interface or sends a response prohibition signal to a dedicated test line during diagnostic operation, and forces other connected devices to stop operating or respond. By prohibiting this, the purpose is to suppress the increase in volume due to internal folding and to enable diagnosis using actually operating hardware.

[Means for solving problems]

Means for solving the problem will be explained with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, an interface control circuit 1.1-1 exchanges data with a common bus, and is a circuit to be diagnosed. This interface control circuit 1.1-1 includes a driver 3 and a receiver 4.
When set, the device test mode latch 2.2-1 sends out a reset signal to the common bus or sends out a response prohibition signal to the test line 5.

The test line 5 is for transmitting a response prohibition signal to other devices.

[Effect]

As shown in FIGS. 1 and 2, in the present invention, the test mode latch 2 is set to send a reset signal to the common bus, or the test mode latch 2-1 is set to send a response prohibition signal to the test line 5. While the driver 3 sends control signals, data, and addresses to the common bus while other devices are held in the initialized state or inhibited from responding, the control signals, data, and addresses sent to the common bus are is taken in through the receiver 4 to diagnose the operation of the interface control circuit 1.

Therefore, with a simple configuration, the interface control circuit 1
It is possible to diagnose the operation of the driver 3 and receiver 4 which are directly connected to the common bus, which could not be diagnosed by conventional internal loopback. It becomes possible to perform operational diagnosis including

〔Example〕

Next, the configuration and operation of one embodiment of the present invention will be explained in detail using FIGS. 1 and 2.

FIG. 1 shows a configuration diagram of an embodiment in which diagnosis is performed by using a test mode latch 2.

In FIG. 1, an interface control circuit 1 transmits control signals (strobe signals, response signals, etc.) to a common bus.
, addresses, and data are exchanged.

The test mode latch 2 is set when diagnosing the operation of the interface control circuit 1. By setting this test mode latch 2, a system reset signal is sent to the common bus to hold all other devices in their initialized state. Therefore, no matter what bus cycle the illustrated interface control circuit l performs on the common bus, it is ignored by other devices and does not affect other devices.

The driver 3 sends control signals, addresses, and data to the common bus.

The receiver 4 receives control signals, addresses, and data from the common bus.

The address output latch 5-1 and data output latch 5-2 hold addresses and data to be sent to the common bus.

Address input latch 6-1, data input latch 6-2
is used to capture and hold addresses and data from the common bus.

The mask control circuit 7-1 sends control signals (such as strobe signals) to the common bus.

The slave control circuit 7-2 takes in control signals (response signals, etc.) from the common bus.

The address setting register 7-3 is used to set an address to be accessed.

Next, the operation will be explained.

In Figure 1, the test mode is set to launch 2 and 5.
Sends the YSRST (system reset) signal to the common bus. This keeps all other devices connected to the common bus in an initialized state and ignores any bus cycles performed on the common bus. Therefore, in this state, arbitrary addresses are sequentially set in the address setting register 7-3 and input to the slave control circuit 7-2, and the common bus is accessed under the control of the mask control circuit 7-1. do. At this time, address output latch 5
-1, the address and data sent to the data output latch 5-2 are sent to the common bus via the driver 3, and the address and data fetched from the common bus via the receiver 4 are sent to the address input latch 6-1, It is held by the data input latch 6-2. The operation of the interface control circuit 1 is diagnosed based on the control signals, addresses, and data sent to the common bus and the control signals, addresses, and data taken in from the common bus.

As described above, a system reset signal is sent to the common bus by sending a system reset signal to the test mode latch 2 to hold all other devices in the initialized state, and during this time, a control signal is sent to the common bus via the driver 3. It is possible to diagnose the operation of the interface control circuit 1 under the same conditions as the normal operating condition by transmitting a control signal and taking in a control signal from the common bus via the receiver 4.

FIG. 2 shows a configuration diagram of another embodiment in which diagnosis is performed by sending a response prohibition signal to the test line 5.

In FIG. 2(a), the test mode latch 2-1 is
This is set when diagnosing the operation of the interface control circuit 1. After the interface control circuit 1-1 obtains control of the common bus, by setting the test mode latch 2-1, a response prohibition signal is sent to the test line 5, and all other devices are blocked even if they are not accessed. Even if you do, you will be instructed not to respond.

The test line 5 is for transmitting a response prohibition signal to other devices connected to the common bus.

The arbiter 6 performs exclusive management of which device is given control of the common bus.

Next, the operation of the configuration shown in FIG. 2 (A) will be explained using FIG. 2 (B).

In FIG. 2(b), device A sends Bus Request A' to arbiter 6 via the common bus.

Arbiter 6 replies to device A with "Bus Grant A." Correspondingly, device A recognizes that the previous device x is “
The transmission of the “Bus Busy” signal is stopped and the “Data
When "5trobe" or "Data Ack" is not output on the bus, "Bus Busy"
Send a signal to gain control of the common bus. and,
A response prohibition signal according to this embodiment is sent to the test line 5 to instruct other devices not to respond even if the own device is selected.This response prohibition signal is sent to the test line 5. In the meantime, a control signal such as "Data 5trobe" is sent to the common bus via the driver 3, and
A control ffl signal is taken in from the common bus via the receiver 4 to diagnose the operation of the interface control circuit 1-1.

As mentioned above, device A etc.
``After transmitting a signal to the arbiter 6 to acquire the control right of the common bus, and after transmitting a response prohibition signal to the test line 5 to make other devices unresponsive, control signals etc. are transmitted via the driver 3. By transmitting control signals to the common bus and fetching control signals from the common bus via the receiver 4 and diagnosing the operation of the interface control circuit 1-1, the interface control circuit 1-1 is operated in the same state as the normal operating state.
1 operation diagnosis can be performed.

〔Effect of the invention〕

As explained above, according to the present invention, after setting the test mode latch 2 and sending a reset signal to the common bus, or after acquiring control of the common bus, the test mode launch 2-1 is set and a response prohibition signal is sent. is sent to the test line 5, and while other devices are held in the initialized state or inhibited from responding, the driver 3 sends control signals, data, and addresses to the common bus, and the control signals sent to this common bus. Since a configuration is adopted in which signals, data, and addresses are received via the receiver 4 and the operation of the interface control circuit 1 is diagnosed, the operation of the interface control circuit 1.1-1 can be diagnosed using a simple circuit configuration. I can do it. In addition, operation diagnosis can be performed using the same circuit configuration as in normal operation, especially for driver 3 directly connected to the common bus, which could not be diagnosed by conventional internal loopback.
Operation diagnosis including the receiver 4 can be performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a block diagram of another embodiment of the present invention, and FIG. 3 is an explanatory diagram of a prior art. In the figure, l, 1-1 is an interface control circuit, 2.2-
1 represents a test mode latch, 3 represents a driver, 4 represents a receiver, and 5 represents a test line. Patent applicant: BFN Co., Ltd. Patent attorney Oka 1) Morihiroto

Claims (2)

[Claims] (1) In a diagnostic method for diagnosing an interface control circuit connected to a common bus, there are two components: a driver (3) that sends control signals, addresses, and data to the common bus, and a receiver (3) that takes in control signals, addresses, and data from the common bus. 4), an interface control circuit (1) consisting of a control circuit that controls a common bus, and a test mode latch (2) that sends a reset signal to the common bus. While the test mode latch (2) is turned on and a reset signal is sent to the common bus, the control signal sent from the driver (3) to the common bus is sent to the receiver (4).
The interface control circuit (1)
1. An interface control circuit diagnostic method, characterized in that it is configured to diagnose. (2) In a diagnostic method for diagnosing an interface control circuit connected to a common bus, a driver (3) sends control signals, addresses, and data to the common bus, and a receiver (3) receives control signals, addresses, and data from the common bus. 4), an interface control circuit (1) consisting of a control circuit for controlling a common bus, and a test line (5) for transmitting a response prohibition signal for prohibiting responses to the common bus; 1), while the interface control circuit (1) that has acquired control of the common bus is sending a response prohibition signal to the test line (5), the driver (3) is not connected to the common bus. An interface control circuit diagnostic method characterized in that the interface control circuit (1) is diagnosed by receiving a transmitted control signal or the like by the receiver (4).