JPH0363835A - Firmware diagnostic device - Google Patents

Abstract

PURPOSE:To recognize the access status of a universal register in a wide range by storing the address of firmware at the time when a microinstruction which makes access an arbitrary universal register with a decoder is stored in a memory sequentially with a program counter at every detection of the microinstruction. CONSTITUTION:When the firmware running microinstruction of a controller 1 is an instruction to make access the universal register I, the decoder 30 outputs an enable signal c1, and the address of the firmware at that time is stored in the memory 40 via a signal line (a). Next, when the instruction to make access the universal register II is issued, the decoder 30 outputs an enable signal c2, and the address is stored in the memory 50, and similarly, the address is stored in the memory 60 with an enable signal c3 in the case of the universal register III. In such a manner, it is possible to recognize the access status of the universal register in a wide range.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a firmware diagnostic device.

[Conventional technology]

Conventional firmware diagnostic devices stop the program at an arbitrary address and only retain the contents of general-purpose registers and the running address of the firmware up to the stop address, but do not retain the address of the firmware that accessed the general-purpose register.

[Problem to be solved by the invention]

The conventional firmware diagnostic device described above only holds a certain limited running address of the firmware, so when focusing on a certain general-purpose register, there is only a limited range of information, so it is difficult to access the general-purpose register from a long time before that point. The disadvantage is that it is difficult to investigate the situation.

A program counter that counts running addresses of the firmware, a decoder that individually detects microinstructions that access a plurality of general-purpose registers, and a memory that stores the address of the firmware at that time when the microinstruction is detected. and is configured such that each time the decoder detects a microinstruction that accesses an arbitrary general-purpose register, the address of the firmware at that time is sequentially stored in the memory from the program counter.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. A control device 1 with built-in firmware that realizes normal functions includes, for example, a 16-bit program counter 10 and an instruction register 20. A program counter output signal line a, which is an output signal line, and an instruction register output signal 41b, which is an output signal line of the instruction register 20.
It is connected to a diagnostic device 2 for diagnosing the firmware of the control device 1 via. This diagnostic device 2 decodes microinstructions input through the signal line, detects individual instructions to access general-purpose registers', and outputs enable signals 01 to C3 in a decoder 30.
Each time a register access command is detected, the memory 40, 50, and 60 sequentially store data received from the control device 1 via the signal line a as input data.

Next, the operation will be explained.

In FIG. 1, while the firmware of the control device 1 is running,
When the microinstruction is an instruction to access the general-purpose register ■, the decoder 30 outputs an enable signal CI, and the address of the firmware at that time is stored in the memory 40 via the signal line a. When an access command is issued, the decoder 30 outputs an enable signal C2, and the address is stored in the memory 50. Similarly, in the case of general-purpose register ■, enable signal C3
As a result, the address is stored in the memory 60.

The memory addresses of the memories 40, 50, and 60 are incremented by 1 each time they are set, and when they reach the final address, they are returned to the starting address.

Therefore, if the firmware is set to stop at a certain address, the corresponding general-purpose registers 1. The address of the firmware that accessed II and nI is stored.

In this way, the access status of a wide range of general-purpose registers can be known.

〔Effect of the invention〕

As described above, the present invention has the advantage that access conditions of a wide range of general-purpose registers can be known by using a special diagnostic circuit.

Claims (1)

[Claims] A program counter that counts running addresses of firmware, a decoder that individually detects microinstructions that access a plurality of general-purpose registers, and a memory that stores the address of the firmware at that time when the microinstruction is detected. 1. A firmware diagnostic device comprising: a firmware diagnostic device, wherein each time the decoder detects a microinstruction that accesses an arbitrary general-purpose register, the address of the firmware at that time is sequentially stored in the memory from the program counter.