JPH0414367B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microcomputer development support device having a microprocessor and a real-time tracer.

[Conventional technology]

A block diagram of a conventional example of a microcomputer development support device is shown in FIG. Conditions for stopping the execution of the program by the microprocessor 1 (hereinafter referred to as break conditions) are set in the break control circuit 3 in advance. Microprocessor 1
selects the instruction code stored in the emulation memory 2 via the address bus 6, fetches it via the data bus 7, executes this instruction, and the real-time tracer 4 executes the processing executed by the microprocessor 1. process address bus information,
Information such as data bus information and input/output port values of the microprocessor 1 is stored. When the break conditions set in advance in the break control circuit 3 are met, the break signal S is output from the break control circuit 3 to the microprocessor 1, and the microprocessor 1 stops executing the program and manages the system. The supervisor processor 5 enters the supervisor processor 5 mode.
was reading out information stored in the real-time tracer 4 and performing debugging.

[Problem that the invention seeks to solve]

However, among the instructions executed by the microprocessor 1, there is an instruction that skips the next fetched instruction, and conventional microcomputer development support equipment does not distinguish between skipped and unexecuted instructions and executed instructions. The problem is that the data is stored in the real-time tracer 4 without being processed, causing confusion when the supervisor processor 5 debugs the program, resulting in poor efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide a microcomputer development support device capable of determining skipped and unexecuted instructions.

[Means for solving problems]

The microcomputer development support device of the present invention is characterized in that when the microprocessor skips an instruction fetched, it outputs a skip signal indicating that the instruction is being skipped, and the real-time tracer stores this skip signal.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a microcomputer development support device according to an embodiment of the present invention. When the microprocessor 11 fetches a skip instruction and the conditions for skipping are met, it replaces the next fetched instruction with a no-operation instruction (hereinafter referred to as a NOP instruction) and executes it. Skip signal indicating execution
Output SK from skip terminal T. The real-time tracer 14 stores address bus information, data bus information, input/output port values of the microprocessor 11, etc. of the processing process executed by the microprocessor 11, and also has an internal skip memory to The skip signal SK output from the SK is stored. The write control circuit 8 writes the skip signal SK output from the skip terminal T of the microprocessor 11 to the skip memory in the real-time tracer 14. That is, in this embodiment, a microprocessor 11 having a skip terminal T is installed in place of the microprocessor 1 in the conventional example shown in FIG. An integrated control circuit 8 is added.

Now, the skip instruction is sent to the microprocessor 11.
When the next fetched instruction is fetched and the conditions for skipping are met, the next fetched instruction is replaced with the NOR instruction and executed, and the skip signal SK is sent from the skip terminal T of the microprocessor 11.
is output, and this skip signal SK is written into the skip memory in the real-time tracer 14 by the write control circuit 8.

Therefore, when debugging, the supervisor processor 5 uses the skip signal SK stored in the skip memory in the real-time tracer 14.
By reading , it is possible to determine whether the instruction at the traced address has been skipped.

〔Effect of the invention〕

As described above, according to the present invention, instructions that have been skipped and are not being executed can be easily determined, so that efficient real-time debugging can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a microcomputer development support device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. 11...Microprocessor, 2...Emulation memory, 3...Break control circuit, 14
... Real-time tracer, 5 ... Supervisor processor, 6 ... Address bus, 7 ... Data bus, 8 ... Write control circuit, T ... Skip terminal, SK ... Skip signal.

Claims (1)

[Scope of Claims] 1. In a microcomputer development support device having a microprocessor and a real-time tracer, when the microprocessor skips a fetched instruction, it outputs a skip signal indicating that it is skipping, A microcomputer development support device characterized in that a tracer stores the skip signal.