JPH05150976A - Microprogram rewriting method in central processing unit - Google Patents

Abstract

PURPOSE:To rewrite a microprogram in a central processing unit during the operation of the central processing unit by providing the central processing unit containing a microinstruction dedicated for microprogram rewrite, and executing a microprogram rewrite instruction by the central processing unit. CONSTITUTION:A main memory device 1 includes software 2 which prepares the rewrite of the microprogram based on information inputted from a device operator, a microprogram rewrite address storage area 3 generated by the software 2, and a microprogram rewrite data storage area 4. The central processing unit 6 is equipped with a main memory device access control part 7, a microprogram control part 8 equipped with a microprogram storage area 10, and an arithmetic processing control part 11. When the software 2 executes the microprogram rewrite instruction, the microprogram 12 in the central processing unit 6 is operated, which rewrite part of the program in the microprogram area 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus, and more particularly to a microprogram rewriting method of a central processing unit controlled by a microprogram stored in a read / write memory (hereinafter referred to as RAM).

[0002]

2. Description of the Related Art Conventionally, an information processing apparatus suspends the operation of the apparatus when it is necessary to rewrite the microprogram of the central processing unit controlled by the microprogram in the apparatus during the operation of the apparatus. In addition, the control clock of the central processing unit is stopped and the microprogram in the central processing unit is rewritten by using a maintenance diagnostic device or the like. Or, by using software, rewrite the load image of the microprogram in the external storage device, stop the operation of the device, restart the device, and load the rewritten microprogram load image in the external storage device. It was a method of rewriting a microprogram.

[0003]

In the above-mentioned conventional system, it is necessary to stop the operation of the apparatus and further stop the control clock of the central processing unit. It has the drawback that it cannot rewrite microprograms.

[0004]

A central processing unit microprogram rewriting method according to the present invention comprises a microprogram execution control section, a microprogram storage area constituted by a read / write memory, and a microprogram rewriting dedicated microinstruction. It includes a central processing unit including the same, a main memory including a microprogram rewriting instruction information storage area and a microprogram rewriting information storage area, and the central processing unit executes a microprogram rewriting instruction.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of the present invention.

The main memory 1 is a software 2 for preparing for rewriting a microprogram based on information input by a device operator, a microprogram rewriting address storage area 3 created by the software 2, and microprogram rewriting data. The storage area 4 is included.
The central processing unit 6 uses a main memory access control unit 7, a micro program execution control unit 9, and a micro program control unit 8 which are used when accessing the main memory unit 1, and a micro program control unit 8. An arithmetic processing control unit 11 for controlling the function of the original central processing unit is provided. The microprogram storage area 10 is composed of RAM.

The main memory access path 5 is a communication path connecting the central processing unit 6 and the main memory 1.

Although not shown in detail, the microprogram execution control unit 9 in the microprogram control unit 8 has a "microprogram rewrite address storage register" indicating a rewrite address in the microprogram storage region 10 and a new register. It has a "microprogram rewriting data storage register" for storing the data image of the microprogram to be rewritten.
In addition, a "microprogram rewrite address storage register" and a "microprogram rewrite data storage register" are used in the microprogram storage area 10, and a microprogram instruction that controls rewriting of a desired microprogram storage area 10 is operated. Microprogram for program rewriting 1
2 is stored and operates.

Next, the operation when the necessity of rewriting the microprogram for controlling the central processing unit 6 arises during system operation will be described.

In the microprogram storage area 10 of the central processing unit 6, the "arithmetic processing microprogram" and the microprogram 1 for microprogram rewriting processing are provided.
2 is stored from an external storage device by some means at the stage of starting up the device.

First, the software 2 uses the "microprogram rewriting address" and "microprogram rewriting data" input by the operator from the console to store the microprogram rewriting address storage area 3 and micro The data is stored in the program rewriting data storage area 4, and the microprogram rewriting instruction is notified to the central processing unit 6 through the main memory access path 5.

The microprogram control unit 8 in the central processing unit 6 always waits for an instruction in the main memory access path 5 when the arithmetic processing control operation is unnecessary. When the microprogram rewrite command is received in this state, the microprogram execution control unit 9 in the microprogram control unit 8 activates the microprogram rewrite processing dedicated microprogram 12 in the microprogram storage area 10. The activated microprogram rewrite processing dedicated microprogram 12 is stored in the microprogram rewrite address storage area 3 and the microprogram rewrite data storage area 4 in the main storage device 1 via the main storage device access control unit 7. The "microprogram rewrite address" and the "microprogram rewrite data" are read out and stored in the microprogram rewrite address storage register and the "microprogram rewrite data storage register" in the microprogram execution control unit 9, respectively.

Further, the microprogram rewrite processing-dedicated microprogram 12 stores the contents of the microprogram at the address indicated by the "microprogram rewrite address storage register" in the area of the microprogram storage area 10 in the "microprogram rewrite data storage register". The micro instruction for instructing the micro program execution control unit 9 to rewrite the contents is executed. This completes the rewriting of the desired microprogram,
The process shifts to the next arithmetic processing control command reception state.

[0015]

As described above, according to the present invention, when the microprogram of the central processing unit controlled by the microprogram needs to be rewritten, the operation of the apparatus including the central processing unit and the central processing unit are stopped. Since it becomes possible to rewrite the microprogram in the central processing unit without stopping the control clock of, the microprogram can be rewritten without stopping the operation of the device in a device characterized by continuous operation for 24 hours. I can.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention.

[Explanation of symbols]

1 Main Memory 2 Software 3 Micro Program Rewrite Address Storage Area 4 Micro Program Rewrite Data Storage Area 5 Main Memory Access Path 6 Central Processing Unit 7 Main Memory Access Control Section 8 Micro Program Control Section 9 Micro Program Execution Control Section 10 Micro Program storage area 11 Arithmetic processing control unit 12 Micro program Rewriting processing dedicated micro program

Claims (1)

[Claims] 1. A central processing unit including a microprogram execution control unit, a microprogram storage area constituted by a read / write memory, a microprogram rewriting dedicated microinstruction, a microprogram rewriting instruction information storage area, and a microprogram. A central processing unit microprogram rewriting method, comprising: a main memory including a program rewriting information storage area, wherein the central processing unit executes a microprogram rewriting instruction.