JPH02281349A - Microcomputer - Google Patents

Abstract

PURPOSE:To give a function to execute the inter-memory operation with one instruction by providing an arithmetic processing device and reading in contents of plural temporary registers and storing operation results in index registers. CONSTITUTION:An arithmetic instruction is fetched, and contents of a memory M(X) 9 addressed by an index register X1 are stored in a temporary register A6 through a data bus 5. Next, contents of a memory M(Y) 10 addressed by an index register Y2 are stored in a temporary register B7 through the data bus. Contents of registers A6 and B7 are read into an arithmetic processing device ALU 6. The operation result is stored in the memory M(X) 9 through the bus 5. Thus, the operation between memories M(X) 9 and M(Y) 10 addressed by two registers X1 and Y2 is performed with one instruction, and the result is stored in a memory RAM 4.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention has two storage device address instruction registers, one
The present invention relates to a microcombiator that has a function of executing operations between two storage devices only by executing instructions. [Prior Art] Conventional microcomputers have only one address register that specifies the address of a data memory, and in order to perform an operation between two memories, the address register is used to read one of the memories. The contents of the memory were read into a general-purpose register, then the address instruction register was rewritten to point to the other memory, and an operation was executed between the general-purpose register and the other memory. [Problems to be Solved by the Invention] However, in the conventional technology, in order to perform an operation between two memories, it is necessary to go through a general-purpose register, and the contents of the general-purpose register are not saved. must be saved as necessary, resulting in a decrease in program capacity and execution time efficiency. Further, even if it is not necessary to save the contents of the general-purpose register, a program is always required to store the contents of one memory in the general-purpose register, so there is a problem that the efficiency of the program in terms of capacity and execution time decreases. The present invention aims to solve these problems, and its purpose is to perform arithmetic processing between two memories.
The object of the present invention is to provide a function that can be executed with an instruction using two address registers and without using a general-purpose register. [Means for Solving the Problems] The microcombinator of the present invention (a) has two or more address instruction registers of a storage device, (b) uses two address instruction registers to The present invention is characterized by having a function of reading the contents of two storage devices, performing an operation, and writing the operation result to the storage device specified by one of the address instruction registers during the execution of one instruction. . [Function] According to the above configuration of the present invention, arithmetic processing between two memories can be executed with an instruction using two address specification registers without going through other general-purpose registers.
Program capacity and program execution time can be reduced.

【Example】

The present invention will be described in detail below based on examples. FIG. 1 shows two address instruction registers according to an embodiment of the present invention.
This is a block diagram of a microcomputer that can perform inter-memory operations with one instruction. Index register X (1) and index register Y (2) are address instruction registers of RAM (4), which is a storage device, and are
Each can specify a different RAM address. The memory M(X) (9) whose address is specified by the index register x(1) and the index register
Memory M(Y) whose address is specified by register Y(2)
)(10) and the result of the operation is stored in the memory M(X)(9), the processing within one instruction is as follows. First, an arithmetic instruction is fetched, and then the memory M(X) whose address is specified by the index register
The contents of (9) are stored in temporary register A (6) via data bus (5). Memory M is addressed by zero-order index register Y (2).
(Y) Store the contents of (10) into temporary register B (7) via data bus (5). After that, the contents of temporary register A (6) and temporary register B (7) are read into the arithmetic processing unit ALU (8), and the result of the operation is transferred to the index register via the data bus (5). - Store X(1) in the addressed memory M(X)(9). As described above, it becomes possible to use the two index registers in the l instruction to perform operations between the memories respectively addressed, and to store the results in the memories. Effects of the Invention 1 As mentioned above, the microcomputer of the present invention can perform % processing using program instructions without using other general-purpose registers.
Because it is possible to perform calculations between two memories,
This has the advantage that the program capacity and program execution time can be shortened, and more efficient system control can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a microcomputer according to the present invention. Index register X Index register Y Address bus AM Data bus Temporary register A Temporary register B LU M (X) M (Y)

Claims (1)

Scope of Claims: (a) having two or more storage device address instruction registers; (b) using the two address instruction registers to read and operate the contents of two storage devices; A microcomputer characterized by having a function of writing an operation result to a storage device indicated by one of the address instruction registers during execution of one instruction.