JPH02201662A - Trace control system - Google Patents

Abstract

PURPOSE:To stop trace without interrupting a microprogram by prohibiting write to a trace memory when the set contents of an address match register coincides with a microinstruction address generated in an address control circuit. CONSTITUTION:A register 15, where the arbitrary microinstruction address whose trace is to be stopped can be set from the outside, and a comparing circuit 16, which detects the coincidence between the set contents of the register 15 and the microinstruction address generated in an address control circuit 12, are provided. When the coincidence is detected, the write operation of a trace memory 13 is prohibited by a trace memory control circuit 18, and the trace of the executed microinstruction address is stopped. Thus since the trace can be stopped without interrupting the microprogram during the execution, the efficiency of debugging work can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Field of Industrial Application) The present invention relates to a trace control system suitable for a microprogram control device having a function of tracing execution microinstruction addresses.

(Prior Art) In a computer system equipped with a microprogram control device, the address of the executed microinstruction (execution microinstruction address ) It has been known to add a function to a microprogram control device to trace (). Starting and stopping of this type of tracing can be performed arbitrarily using microinstructions, and this tracing processing provides useful information in the event of the above-mentioned troubles.

(Problem to be Solved by the Invention) As mentioned above, in the past, starting and stopping tracing of execution microinstruction addresses was controlled by microinstructions, so it was necessary to stop tracing while a microprogram was being executed. In this case, by setting a specific microinstruction for stopping trace at the relevant location of the microprogram, the processing of the microprogram can be interrupted at the desired location, the trace can be stopped, and then the processing of the interrupted microprogram can be resumed. I needed to come back. In other words, conventionally, in order to stop tracing the execution microinstruction address, it was necessary to change the program by setting a trace stop 1] microinstruction in the middle of the microprogram, which interrupted the processing of the currently executing microprogram. There was the problem of inviting

Therefore, the problem to be solved by the present invention is to make it possible to stop tracing of the executed microinstruction address at a desired location without changing the microprogram and without interrupting the microprogram being executed.

[Structure of the Invention] (Means for Solving the Problems) The present invention stores trace information including microinstruction addresses for control memory generated by an address control circuit in order from the start of addressing the execution microinstruction address. trace memory, a register in which an arbitrary microinstruction address at which tracing should be stopped can be set externally, and a match between the settings of this register and the microinstruction address generated by the address control circuit described above. a match detection circuit and a trace memory control circuit that controls writing/reading to and from the trace memory, and when a match is detected by the match detection circuit, the trace memory control circuit prohibits write operations to the trace memory. This feature is characterized in that tracing of the executed microinstruction address is stopped.

(Operation) According to the configuration described in section 2, by setting in advance a microinstruction address for which tracing is to be stopped in the above register, when the same microinstruction address as this address is generated by the address control circuit, Tracing of the executed microinstruction address can be stopped without interrupting the microprogram.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of a microprogram control device to which the present invention is applied. In the figure, 11 is a rewritable control memory (hereinafter referred to as WCS) for storing various microprograms consisting of one or more microinstructions, and 12 is a control memory for storing various microprograms consisting of one or more microinstructions. Atonenos control circuit (microinstruction address control circuit, microsequencer) that generates the address (WCS address) of the microinstruction to be executed
It is. Reference numeral 13 indicates a microinstruction address generated by the address control circuit 12, and furthermore, various control information (here, various flags, control signals for the twin line stage, etc.) associated with the execution of the microinstruction specified by the same address, to the execution microcontroller. 1.4 is a trace memory address counter (hereinafter referred to as TRM) that generates the address of the trace memory 13 (TRM address).
(referred to as an address counter).

15 is a register (address master register) in which the microinstruction address at which tracing should be stopped can be set; 16
compares the setting contents of the address match register 5 and the microinstruction address generated by the address control circuit 12, and when a match is detected, sends a valid address match signal 1.
18 is a trace memory control circuit (hereinafter referred to as TRM control circuit) that performs read/write control for the trace memory 3 and count-a-tub control for the TRM address counter 4. T
The RM control circuit 18 starts writing to the trace memory 13 and controlling the count up of the TRM address counter in response to the trace activation signal 19, and also starts the writing and count up control in response to the valid address match signal 17 from the comparison circuit 16. The control is configured to stop. 21 is a destination bus used for transferring various destination data such as data read from the trace memory I3; 22 is a microinstruction AT1 to be set in the address match register 15;
．． This is a source bus used for transferring various types of source data such as No.

Next, the operation of the configuration shown in FIG. 1 will be explained. First, when starting a trace, the microinstruction address at which the trace should be stopped is sent to the address match register 15 via the source bus 22.
Load it into . This loading operation is performed, for example, by executing a maintenance program. In this state, trace is activated using a trace activation microinstruction. As a result, the addresses (microinstruction addresses) of the WC8II are sequentially generated and output from the AT1/S control circuit 12, and the corresponding microinstructions are taken out from the WC8II and subjected to execution. That is, the microprogram to be traced is executed. Note that this microprogram does not have a special microinstruction to stop the trace midway through.

Now, when the above trace activation is applied, the trace activation signal 19 becomes true. When the trace activation signal 19 becomes true, the TRM control circuit 18 sends trace information consisting of the microinstruction address generated and output from the address control circuit 12 and various control information associated with the execution of the microinstruction specified by the same address to the TRM address counter. 14 is started, and the TRM address counter 14 is counted up every time one write cycle corresponding to one microinstruction cycle ends.

The microinstruction address generated and output from the address control circuit 12 is guided to one input of the comparison circuit 16 in addition to the WC 811 and the trace memory 13.

The setting contents of the address match register 15 are introduced to the other input of the comparison circuit 6. The comparison circuit 16 compares the microinstruction address (execution microinstruction address) from the address control circuit 12 and the contents of the address match register 5 (setting microinstruction address), and sets the address match signal 17 to true only when both addresses are equal. Make it.

Address match signal 17 from comparison circuit 16 is guided to TRM control circuit 18. The TRM control circuit 18 is activated in response to the trace activation signal 19, and then the comparison circuit 1 is activated.
When the address match signal 17 from 6 becomes true, writing to the trace memory 13 is prohibited in the next cycle, and counting up of the TRM address counter 14 is stopped. Even in this state, the address control circuit 12 continues address control (microsequence control) to continue the execution of the microprogram to be traced, and there is no possibility that the program will be interrupted.

When the execution of the microprogram to be traced is eventually completed, the read control function of the TRM control circuit 18 is activated. As a result, the TRM control circuit 18 controls reading out the contents of the address of the trace memory 13 specified by the TRM address counter 14 to the destination bus 21;
The control of counting down the TRM address counter 14 every time the reading is performed is repeated. As a result, the destination bus 21 contains trace information when a microinstruction address that matches the contents of the address match register 15 is accessed as specified by the address control circuit 12;
Furthermore, previous trace information is output sequentially, so
Target trace information can be obtained from the data on this bus 21.

[Effects of the Invention] As detailed above, according to the present invention, by setting the address of the microinstruction for which tracing is to be stopped in a register in advance, the execution microinstruction address matches the setting contents of the register. At this point, tracing can be automatically stopped without changing the program by setting a special microinstruction for stopping tracing in the microprogram to be traced, as in the conventional case. That is, according to the present invention, tracing can be stopped without interrupting the microprogram being executed, so that debugging work can be made more efficient.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a microprogram control device to which the present invention is applied. 11... Control memory (WC8), 12... Address control circuit, 13... Trace memory (TRM), 1
4...TRM address counter, 15...Address match register, 16...Comparison circuit, 18...TR
M control circuit. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] In a microprogram control device comprising a control memory in which various microprograms are stored and an address control circuit that generates an address of a microinstruction to be extracted from the control memory and executed, the microinstruction generated by the address control circuit is A trace memory for storing trace information including addresses in order from the start of tracing of execution microinstruction addresses, a register that can be set externally to any microinstruction address at which tracing should be stopped, and the settings of this register. A match detection circuit for detecting a match between the microinstruction address generated by the address control circuit and a trace memory control circuit for controlling writing/reading to/from the trace memory. A trace control method characterized in that, when a match is detected, the trace memory control circuit inhibits write operation of the trace memory and stops tracing of the execution microinstruction address.