JP3030962B2 - Micro program controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microprogram controller, and more particularly, to local memory initialization.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram of a conventional example of a microprogram controller.

[0003] This microprogram control device comprises a microprocessor 21, a control memory 23 and a local memory 2.
4 and a control unit 25 such as an IO and a ROM 22 and were connected by an internal bus 26. Microprocessor 2
1 reads a microprogram from the control storage 23, executes an instruction, and gives an appropriate instruction to the control unit 25 and the like. The local memory 24 is used as a buffer for various controls. Further, in order to operate the microprocessor 21 at high speed, a high-speed SRAM is used for the control memory 23,
The microprogram is stored in the low-speed but large-capacity ROM 22 and stored in the ROM 22 when the device is started up.
It is used by loading it into the control memory 23 which is an AM.

The control memory 23 and the local memory 24
Immediately after the power is turned on at the time of startup, etc., the contents of the SRAM are unknown. Therefore, the data is not determined unless some data is written. Since the data is unknown, after the loading is completed, the microprogram is executed to write the data into the local memory to determine the data.

[0005]

In the above-mentioned conventional microprogram controller, the local memory is initialized by the microprogram. Therefore, the local memory must be initialized after the microprogram starts to be executed. There is a disadvantage in that it takes extra time to initialize the local memory when booting up.

An object of the present invention is to provide a microprogram control device which does not require extra time for initializing a local memory at startup.

[0007]

SUMMARY OF THE INVENTION A microprogram controller of the present invention comprises an address holding means for holding an address of a control memory and a local memory, and adding one to the address of the address holding means to continuously change an address number. Address updating means for increasing, initial data generating means for generating initial setting data to be written to the local memory at the time of initial setting, means for writing initial setting data generated by the initial data generating means to the local memory, control storage of the microprogram Means for starting to write the initial setting data to the local memory at the same time when the loading to the local memory is started.

[0008]

At the time of initialization, the loading of the microprogram from the ROM to the control storage is started, and at the same time, the initialization data is written to the local memory according to the address from the address updating means. Memory is initialized.

[0009]

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

FIG. 1 is a block diagram showing an embodiment of a microprogram control device according to the present invention.

[0011] This microprogram controller has a RO
M1, micro instruction register 2, address register 3, adder 4, initial data generation circuit 5, local memory 6, control memory 7, selectors 8, 9, 10, 1
1 and a microprocessor (not shown).

A microprogram is stored in the ROM 1. The data of the microprogram is read out by the microprocessor at the time of initial setting, held in the microinstruction register 2, and then written in the control memory 7. The address register 3 indicates the addresses of the ROM 1 and the control memory 7 when the microprogram is loaded into the control memory. This address is also used as the address of the local memory 6 at the same time. The adder 4 performs continuous addition of address numbers. When the loading of the microprogram is started, the initial data generating circuit 5 generates initial setting data for initial setting of the local memory 6. The local memory 6 and the control memory 7 are RAMs, and an address is input from the address register 3 via the selectors 9 and 10, respectively.

Next, the initial setting of this embodiment will be described.

First, the microprocessor reads a microprogram from the ROM 1 and stores it in the microinstruction register 2 via the selector 8. The stored data is loaded into the control memory 7 according to the address output from the address register 3. On the other hand, at the same time as the loading, the initial setting data is output from the initial data generating circuit 5 and sent to the internal bus by the selector 11. In the local memory 6, the initial setting data sent to the internal bus is written to the address input from the address register 3 via the selector 9. In this way, when the loading of the microprogram into the control memory 7 is completed, the initialization of the local memory has also been completed. Therefore, the initial setting of the local memory by the microprogram becomes unnecessary.

[0015]

As described above, according to the present invention, when the microprogram is loaded from the ROM into the control memory, the initial setting data is written into the local memory, so that the local memory based on the microprogram is activated after the microprogram is started. This eliminates the need for the initial setting of the program, and has the effect of speeding up the startup of the microprogram.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a microprogram control device according to the present invention.

FIG. 2 is a block diagram of a conventional example of a microprogram control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ROM 2 Micro instruction register 3 Address register 4 Adder 5 Initial data generation circuit 6 Local memory 7 Control storage 8, 9, 10, 11 Selector

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Claims (1)

(57) [Claims] 1. A microprogram control apparatus comprising: a microprocessor; a ROM storing a microprogram; a control memory for storing the microprogram; a local memory; and a means for loading the microprogram into the control memory at initialization. An address holding means for holding an address of a control memory and a local memory; an address updating means for continuously increasing an address number by adding 1 to an address of the address holding means; Initial data generating means for generating data; means for writing the initial setting data generated by the initial data generating means to the local memory; and starting the loading of the micro program into the control storage when the initial setting data for the local memory is started. Writing Microprogram control unit, characterized in that it comprises a means for starting.