JPS6310247A - Tracing circuit - Google Patents

Abstract

PURPOSE:To collect the effective tracer data with no increase of the capacity of a tracer memory capacity by comparing a designated instruction with a microprogram instruction used for the execution of actions. CONSTITUTION:A microprogram control circuit instructs one of various microprogram instructions via a microprogram instruction designating switch line 12 and stores the instruction in a trace start instruction memory circuit 4. Only the microinstructions that are stored in the circuit 4 in an executing process are compared with each other through a comparator 5 for the decision of coincidence. When the coincidence is obtained between both instructions, the addresses of these instructions are stored in a tracer memory 6. Thus it is possible to keep the locus of a microprogram instruction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a trace circuit used in a microprogram control device, and more particularly to a method of storing data in a trace memory.

[Conventional technology]

Conventionally, this type of control device has always stored the address of a microprogram instruction in a trace memory as a means of fault search/evaluation.

[Problem that the invention seeks to solve]

The trace circuit of the conventional microprogram control device described above, when an event occurs in which the address of the microprogram is repeated due to a design error during device evaluation or when a problem occurs, repeats the same address in the trace memory at a certain period, and stores the pattern. is stored up to the memory capacity limit, which requires an increase in trace memory capacity (increases in cost) and has the disadvantage that valid address trajectories cannot be collected.

[Means for solving problems]

The microprogram control device i of the present invention includes a circuit for instructing a trace start command, a trace start command storage circuit for storing the command, a signal output from the storage circuit, and a memory in which the microprogram command is stored. The microprogram instruction decoding circuit has a microprogram instruction decoding circuit that decodes the read instruction, and a circuit that compares/determines the decoded output and stores the microprogram instruction address in the trace memory if a match is found.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

The microprogram control device includes a memory circuit 2 that stores microprogram instructions for operating the functions of each circuit.
, a microprogram address circuit 1 necessary to read out the memory circuit, an address line 10 indicating the state of the address circuit, and information stored in the memory circuit indicated by the address line. The microprogram fff command is sent through the microprogram information line 11.
It has a microprogram instruction decoding circuit 3 for lr decoding. The microprogram instruction decoded by the decode circuit 3 is sent through the microprogram instruction line 14 to a comparison circuit 5 for comparison with the trace start instruction.

On the other hand, in order to instruct the trace start command, the command designated by the microprogram command command switch line 12 is stored in the trace start command storage circuit 4 . The stored command is sent through a trace start command line 13 to a comparison circuit 5 for comparison with the command line 14. Since these two command lines are asynchronous, the comparison circuit 5 outputs the address write signal line 15 if the comparison results in a match based on the clock signal 16 for synchronization. .

The trace start command storage circuit 4 stores the state of the address IfM10 through the write signal line 15, but since the memory capacity is fixed, when the trace memory circuit 6 reaches its capacity, the initial address (first written) is stored again. It is possible to select whether to store the data sequentially from the entered address or to push it out.

The microprogram control circuit specifies one of the various microprogram instructions with a microprogram instruction instruction switch, specifies that instruction with the microprogram instruction instruction switch, and stores the instruction in a trace start instruction storage circuit. In order to execute a certain operation (for example, in the case of a magnetic disk controller, this refers to writing/reading data to/from a magnetic disk device), a group of several microprogram instructions (hereinafter referred to as subroutines) are spliced together and executed. There is. Including subroutines such as response/confirmation operations with higher-level or lower-level devices, or retries in the event of data errors, etc., results in an enormous amount of microprogram steps. Only the instructions are compared and it is determined whether or not there is a match. If there is a match, the trace of the microprogram instruction address ( For example, it is possible to leave information about which address the convolution operation was executed through.

〔Effect of the invention〕

As explained above, the present invention provides a tracer by comprising a circuit that stores an instruction instructed by a microprogram instruction instruction switch, and a comparison circuit that compares the instruction with the microprogram instruction used to execute the operation. This has the effect of allowing effective tracer data to be collected without increasing memory capacity (increasing the number of original songs).゛

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. 1.--Microprogram address circuit, 2.
...Memory circuit, 3...Microprogram instruction decoding circuit, 4...Trace start instruction storage circuit, 5...Comparison circuit, 6...・
Trace memory circuit, 10...Address line, 1
1...Micro program information line, 12...
...Microprogram instruction instruction switch, 13...
...Trace start command line, 14...Microprogram command line, 15...Address write signal, 16...Clock signal.

Claims (1)

[Claims] a trace start instruction storage circuit that stores a trace start instruction; a microprogram instruction decode circuit that decodes a signal output from the storage circuit and an instruction read from a memory in which the microprogram instruction is stored; and the decode output. 1. A trace circuit comprising means for comparing/judging a microprogram instruction address and writing and storing a microprogram instruction address in a trace memory if a match is found.