JPH0330917Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a single-chip microprocessor for evaluation.

(Prior Art) Conventionally, different types of single-chip microprocessors have been manufactured by changing the built-in peripheral circuits in various ways without changing the instruction set of the single-chip microprocessor.

Generally, single-chip microprocessors require hardware emission when creating application programs, and therefore a special single-chip microprocessor called an evaluation single-chip microprocessor is required. For the single-chip microprocessors mentioned above, which differ only in the built-in peripheral circuits, one single-chip microprocessor for evaluation can be manufactured without manufacturing individual single-chip microprocessors for evaluation. It is often used for both purposes. In this case, this single-chip microprocessor for evaluation will reflect differences in the peripheral circuits built into the corresponding individual single-chip microprocessors (whether or not a certain peripheral circuit is built in). As a result, programs created using the evaluation single-chip microprocessor may not run correctly on the corresponding single-chip microprocessor.

(Problem that the invention attempts to solve) Conventionally, this drawback has been addressed by not generating instruction codes that access peripheral circuits that are not built into the language processing program. This drawback could not be overcome without using a language processing program.

It is an object of the present invention to provide a single-chip microprocessor for evaluation that can eliminate the above-mentioned drawbacks, correctly detect differences in built-in peripheral circuits, and operate correctly even during program development.

(Means for Solving the Problems) The single-chip microprocessor for evaluation of the present invention includes a read-only memory for storing machine instructions, and an instruction for reading out and temporarily storing the machine instructions from the read-only memory. a register, an instruction decoder for reading machine instructions from the instruction register, and a control bus, address bus, and data bus for respectively transmitting microprocessor control signals, address signals, and data signals generated by the instruction decoder. , a single chip for evaluation comprising peripheral circuits such as input/output ports, a peripheral circuit selection circuit that selects the peripheral circuit from the control signal and address signal, and a peripheral circuit selection signal bus that transmits the selection signal of the peripheral circuit. - A microprocessor characterized by being provided with a buffer circuit that outputs the peripheral circuit selection signal and the control signal to the outside.

(Example) Next, an example of the present invention will be described using the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

This embodiment includes a read-only memory 11 for storing machine instructions, an instruction register 1 for reading machine instructions from the read-only memory 11 and temporarily storing them, and an instruction decoder 2 for reading machine instructions from the instruction register 1. , a control bus 3, an address bus 5, and a data bus 4 for respectively transmitting microprocessor control signals, address signals, and data signals created by the instruction decoder 2, and peripheral circuits 8 such as input/output ports. Peripheral circuit selection circuit 6 that selects peripheral circuit 8 from control signals and address signals
and a peripheral circuit selection signal bus 7 for transmitting the peripheral circuit 8 selection signal.
In the microprocessor, a buffer circuit 9 outputs peripheral circuit selection signals and control signals to the outside;
10.

Next, the operation of this embodiment will be explained.

The machine instructions stored in the read-only memory 11 are read out and temporarily stored in the instruction register 1. The read machine instructions are decoded by the instruction decoder 2. The command decoder 2 outputs a control signal, a data signal, and an address signal to a control bus 3, a data bus 4, and an address bus 5, respectively, based on the decoded results. The control signal and address signal output to the bus are sent to the peripheral circuit selection circuit 6.
The peripheral circuit selection signal is decoded by the peripheral circuit selection bus 7 and transmitted as a peripheral circuit selection signal to select the peripheral circuit 8. The control signal and peripheral circuit selection signal output to the bus are output to the outside in real time by buffer circuits 9 and 10, respectively.

As described above, the single-chip microprocessor for evaluation of the present invention outputs control signals and peripheral circuit selection signals in real time when the built-in peripheral circuits are accessed. Single chip for evaluation by
You can find out which peripheral circuits are accessed by the microprocessor and how, i.e. write or read, and know the types of peripheral circuits built into the single-chip microprocessor you are planning to use. If so, you can know whether the accessed peripheral circuit is built-in.

(Effects of the invention) As explained above, according to the invention, even if an evaluation single-chip microprocessor is manufactured for multiple single-chip microprocessors with different built-in peripheral circuits, By outputting internal control signals and peripheral circuit selection signals to the outside in real time when peripheral circuits are accessed, it is possible to detect errors in external accesses to peripheral circuits that are not built in. A microprocessor is obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention. 1...Instruction register, 2...Instruction decoder, 3
...Control bus, 4...Data bus, 5...Address bus, 6...Peripheral circuit selection circuit, 7...Peripheral circuit bus, 8...Peripheral circuit, 9...Buffer circuit (for control signals), 10... ...Buffer circuit (for peripheral circuit selection signal), 11...Read-only memory, 12...
...Read/write memory, 13...Program counter, 14...Accumulator, 15...ALU
(Arithmetic logic operation unit), 16...timing control circuit.

Claims (1)

[Scope of utility model registration request] A read-only memory that stores machine instructions, an instruction register that reads the machine instructions from the read-only memory and temporarily stores them, an instruction decoder that reads the machine instructions from the instruction register, and an instruction decoder created by the instruction decoder. a control bus, an address bus, a data bus that transmits control signals, address signals, and data signals of the microprocessor to be processed, peripheral circuits such as input/output ports, and the peripheral circuits from the control signals and address signals; A single-chip microprocessor for evaluation having a peripheral circuit selection circuit and a peripheral circuit selection signal bus for transmitting a selection signal for the peripheral circuit,
A single-chip microprocessor for evaluation, characterized in that a buffer circuit is provided for outputting the peripheral circuit selection signal and the control signal to the outside.