JPS6217837A - Data processing system - Google Patents

Abstract

PURPOSE:To attain efficient microprogram changing operation whose changing operation is easy by forming a microprogram chaning instruction and a conversion table. CONSTITUTION:The address 62 of the microprogram chaning instruction 6 is a relative address of a microprogram and data 63 are its chaning data. These address 62 and data 63 are set up in an address register 7 and a data register 8 respectively. A table 9 stores the base values 91-94 of an absolute addresses and can be accessed by the upper 2 bits of the relative address. The base values 91-94 are respective leading absolute addresses of four modules 51-54 constituting the microprogram 5. The base value obtained from the table 9 by the upper 2 bits of the relative address is added to the base value of the relative address by an adder 10 to find out the absolute address.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a data processing system controlled by a microprogram, and particularly to a method for changing the microprogram.

(Prior Art) In a data processing device controlled by a microprogram, due to the occurrence of a pseudo failure or a change in the device configuration, it may be necessary to change the microprogram owned by the data processing device while the data processing device is operating.

Generally, for such a need, a microprogram change instruction is provided to instruct a change in the contents of the microprogram. Conventionally, this type of microprogram change instruction has included microaddress change data 7 in the instruction content to indicate the storage location of the microprogram to be changed in main memory or control memory. Therefore, by executing one microprogram change instruction, the microprogram could be changed by one step.

(Problems to be Solved by the Invention) In the conventional data processing system described above, when it is necessary to change the contents of change points scattered in a microprogram, it is necessary to write a large number of microprogram change instructions. However, microprograms whose entire structure is relocatable have the disadvantage that calculating addresses in real memory and branch destination addresses takes considerable time and is prone to errors.

Furthermore, if microprograms with the same content have different configurations depending on the device model, there is also the complexity of having to prepare a group of microprogram change commands for each device model. The purpose is to store a microprogram change instruction consisting of the relative address of the microprogram and change data in order to change the microprogram, and the base value of the absolute address when converting the relative address of the microprogram to an absolute address. A table is provided, and the relative address of the microprogram is converted into an absolute address, which is a storage location in main memory or control memory, using the microprogram change instruction and the table, and whether or not the base value is not a specific value is determined. By determining whether or not to change the data section of the microprogram, the above disadvantages can be removed, and the address on real memory can be easily changed.
Another object of the present invention is to provide a data processing system configured to perform accurate calculations.

(Means for Solving the Problems) A data processing system according to the present invention includes a control memory, a main memory, and an arithmetic circuit.

Control memory is for storing microprograms.

The main memory is used to store microprogram change instructions consisting of a relative address of a microprogram and change data in order to change the microprogram, as well as a base value of an absolute address when converting a relative address of a microprogram to an absolute address. It is equipped with a table.

The arithmetic circuit converts the relative address of the microprogram into an absolute address that is a storage location inside the main memory or control memory using the microprogram change instruction and table, and also checks whether the base value is a specific value or not. This is to determine whether or not to change the data of the microprogram.

(Example) Next, the present invention will be described in detail with reference to the drawings.

In FIG. 1, 1 is a processing unit, 2 is a main memory for storing programs and data, 3 is an arithmetic circuit for sequentially reading and executing programs stored in the main memory 2, and 4 is a storage for microprograms. Then, arithmetic circuit 3
5 is a microprogram composed of four modules, 6 is a microprogram change instruction stored in main memory 2, 7 is an address register, 8 is a data register, 9 is a daple, and 10 is a The adder 11 is a detection circuit.

The microprogram change instruction 6 is composed of an instruction code 61, an address 62, and data 63. Address 62 is the relative address of the microprogram to be changed, and data 63 is the changed data.

Further, the address register 7 and data register 8 are reset by the arithmetic circuit 3 via the signal line 101 with the address 62 and data 63 given by the microprogram change instruction 6, respectively.

Table 9 is used for address conversion and stores absolute address base values old to 94, and is accessed using the upper two bits of the relative address. Base value 91~9
4 is the start absolute address of each of the four modules 51 to 54 making up the microprogram 5. In this sense, it is not necessary to physically store the four modules consecutively in the main memory 2.

The adder 10 adds the base value accessed from the table 9 using the upper two bits of the relative address and the lower value of the relative address. This is an absolute address indicating the storage location of the program.

The detection circuit 11 detects the internal base values 91 to 94 of the table 9.
This is a circuit for detecting whether or not is "0". Only when the base value is not @0#, the arithmetic circuit 3 is controlled via the signal line 110 to change the data of the microprogram. Here, it is assumed that the base value @O'' does not exist in the module.In other words, it is determined on a module-by-module basis whether or not to change the data in the module. In this case, if you set the base value of the corresponding module in Table 9 to "0#," the microprogram change command used in the device (which has the same microprogram as the previous device) in which that module also exists can be used. This means that the group can be used as is, and there is no need to prepare a microprogram change instruction group for each device model.

By using the address conversion means and data modification method described above, the target microprogram stored in the main memory 2 can be modified using its relative address.

In this embodiment, in order to avoid complexity, descriptions of circuits that are not directly related to the present invention are omitted. In this embodiment, the specific value of the base value is set to "O", but it goes without saying that other values may be used.

(Effects of the Invention) As described above, the present invention includes a microprogram change instruction consisting of a relative address of the microprogram and change data, and a process of converting the relative address of the microprogram into an absolute address in order to change the microprogram. A table is provided to store the base value of the absolute address at the time of execution, and the relative address of the microprogram is converted to an absolute address which is the storage location in the main memory or control memory using the microprogram change instruction and the table. By determining whether or not to change microprogram data based on whether the base value is not a specific value, microprogram change operations can be easily performed, resulting in efficient microprogram change processing. There is an effect that 0 can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of a data processing system according to the present invention. 1... Processing device 2... Main memory 3... Arithmetic circuit 4... Control memory 5... Micro program 6... Micro program change instruction 7... Address register 8... Data register 9...Table 10...
・Adder 11...Detection circuits 51 to 54・
...Module 61-63...Instruction fields 91-94...Address 101-11.0...
Signal Gen Patent Applicant NEC Corporation Representative Patent Attorney Hisashi Inoro p+-10-

Claims (1)

[Claims] a control memory for storing a microprogram; a microprogram change instruction consisting of a relative address of the microprogram and modification data for modifying the microprogram; and converting the relative address of the microprogram into an absolute address. a main memory provided with a table for storing the base value of the absolute address of the microprogram, and a storage location of the relative address of the microprogram within the main memory or within the control memory using the microprogram change instruction and the table; and an arithmetic circuit for converting the absolute address to the absolute address and determining whether or not to change the data of the microprogram based on whether the base value is not a specific value. Characteristic data processing system.