JPH0245207B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data processing device, and more particularly to a stack device that realizes a high performance stack machine architecture, such as the B6500 manufactured by Burroughs Corporation in the United States, which is a famous commercial computer.

In order to efficiently implement a stack machine architecture, conventionally, a high-speed register was provided to store a part of the main memory that implements the stack. For example, the Burroughs B6500 has two high-speed registers, and the Heuretsu Patscard HP3000 has four.
It was equipped with several high-speed registers. On the other hand, with these computers, when switching job programs,
The data stored in the high-speed registers was flushed out to main memory, and then the job program started running.

Therefore, as a high-speed register, it is possible to store a larger number of words (for example, 128 words or
When equipped with a high-speed register stack that stores 256 words (256 words), it takes a lot of time to process the data to the main memory when switching job programs, resulting in a large amount of wasted time for program execution. It was becoming.

The object of the present invention is to solve these drawbacks by providing multiple sets of register stacks each consisting of a large number of words in a central processing unit, and executing a job program by switching between these register stacks and using the register stacks. , when changing the register stack, the data accumulated in the previously used register stack can be flushed out to main memory in parallel with the execution of the new job program. It is an object of the present invention to provide a stack device equipped with a control mechanism that minimizes performance deterioration due to switching by efficiently performing switching.

According to the present invention, a plurality of sets of register stacks each consisting of a plurality of words are controlled in a last-in, first-out format, and a main memory that stores data evicted from the register stacks in a last-in, first-out format. , an arithmetic processing unit and one job program are executed using one of the register stacks, and when switching to another job program occurs, processing is performed using the other register stack. At the same time, it is equipped with a control means for expelling the data accumulated in the register stack that has been used so far to the main memory, so that the register stack can be changed when the job is changed. A stacking device is obtained which is characterized by efficient stacking.

Next, one embodiment using the present invention will be described in detail. In this embodiment, a case will be described in which there are two sets of register stacks.

The figure is a block diagram showing one embodiment of the present invention. Two sets of register stacks 1 and 2 consisting of a plurality of words, and a stack pointer 11 indicating the highest position where data of register stacks 1 and 2 is stored.
and 12, a main memory device 3 that stores the data evicted from the register stacks 1 and 2 in separate areas, and a top position of the area from which the stacks 1 and 2 of the main memory device 3 are evicted, respectively. Stack pointers 21 and 22, arithmetic processing unit 4,
It is composed of a data register 5 that exchanges data with the main memory 3, an instruction register 6 that temporarily stores instructions retrieved from the main memory 3, and a control means 7.

Register stacks 1 and 2 are commercially available ICs from Texas Instruments (TI).
This is achieved by combining SN74189.
Stack pointers 11 and 12 are 8-bit long counts when the register stacks 1 and 2 are, for example, 256 words, and are realized by commercially available binary counter ICs. The main memory device 3 corresponds to the main memory device of a conventional computer and is realized by a commercially available IC memory.

The stack pointers 21 and 22 are stored in the main memory 3.
If the stack area is, for example, 64K words, it is a 16-bit counter, which is realized by a commercially available binary counter. The arithmetic processing unit 4 corresponds to an arithmetic logic unit (ALU) in a normal computer, and is realized by combining a commercially available SN74181. The data register 5 and the instruction register 6 are for storing data or instructions of a fixed length, and are realized by combining a D-type flip-flop SN7474, which is a commercially available IC. On the other hand, the control means 7 controls the execution of instructions using the arithmetic processing unit 4, data register 5 and instruction register 6, and also controls the register stacks 1 and 2, stack pointers 11, 12, 2.
1 and 22 control registers 41, 42, 51 and 5
2. Control Controls data exchange between the flip-flops 61, 62 and 70, the main memory 3, and the register stacks 1 and 2, and is realized by combining commercially available gate circuits and ICs such as flip-flops.

First, a situation in which one job program 1 is executed using register stack 1 will be described. When execution shifts to this job program, register stack 1 is empty, so stack pointer 11 indicates the lowest position and is 0. Instruction register 6 and data register 5
When the execution proceeds using the and arithmetic processing unit 4,
As data is stored in register stack 1, stack pointer 11 is updated to point to the upper position of register stack 1. Execution of one job program 1 is performed using register stack 1 in this way.

Next, when switching to another job program 2 occurs, the data currently stored in register stack 1 is transferred to stack area 3 of main memory 3.
After reverting to 1, you need to run a new job. Regarding this, in this embodiment, when a job program is changed, the accumulation of data generated during execution is switched to register stack 2 instead of register stack 1, and register stack 2 is used to store a new job program. Start execution of job program 2. On the other hand, when executing a new job program 2, the data accumulated in the register stack 1 (word i in the figure) is transferred to the main memory 3 by using the time period when the main memory 3 is not accessed. stack area 31 (n+1 in the figure)
from address n+i).

On the other hand, before completing the operation of moving the data in register stack 1 to stack area 31 in main memory 3, it is necessary to prohibit access to this data while a new job program is being executed. (Such situations do not occur very often). For this reason, when changing job programs, address [n+1] and address [n+i] are set in registers 41 and 51 of control means 7, and execution of a new job program 2 is started. and,
When accessing data accumulated in the stack area in the main memory 3 during execution of a new job program 2, before the expulsion process is completed (when the flip-flop 61 is "1"), A process is performed using the registers 41 and 51 to check whether or not the data is relevant. and,
If so, one method is to wait for the eviction process to finish, or another method is to fetch the corresponding data from register stack 1.

The execution of job program 2 is processed using register stack 2 simultaneously with the execution of job program 1.

Next, when execution switches from job program 2 to job program 1, the data stored in register stack 2 regarding job program 2 is moved to the location indicated by stack pointer 22 in stack area 32 of main memory 3. be transferred.

At this time, as in the case of moving from job program 1 to job program 2, registers 42 and 52 are used to protect the data area.

On the other hand, when execution of job program 1 is started, stack pointer 11 is initially set to 0. Then, execution proceeds using register stack 1, and processing proceeds while data is accumulated and removed on register stack 1. At this time, if the data in register stack 1 becomes empty and more is needed in the execution of an instruction,
Processing is continued by moving the data evicted from the stack area 31 of the main memory 3 from the location indicated by the stack pointer 21 to the register stack 1.

The control means 7 performs the control described above. Here, the control flip-flop 70 controls register stacks 1 and 2, stack pointers 11, 21, and 1.
2, 22, 16 bit registers 41, 51 and 42,
For example, if it is "0", register 1 is being used, and if it is "1", register 2 is being used. Control flip-flops 61 and 62 each indicate whether or not the data in register stacks 1 and 2 has been saved to the main memory 3. For example, if it is "1", it means that the data has not been saved yet. , register stack 1 or 2
indicates that data remains.

Although the case where two register stacks are provided has been described above, it is possible to provide a plurality of register stacks in order to cope with the case where there are a plurality of job programs. At this time, the corresponding number of stack pointers, registers of the control means 7, and control flip-flops are provided, and the control flip-flop 70 is provided with the necessary number of bits to indicate a plurality of register stacks instead of one bit. This is realized by Further, control of the register stack is realized by using register stacks in a ring shape in numerical order.

As described above regarding the present invention, it is possible to efficiently change register stacks as job programs are changed, and the effects thereof are significant.

[Brief explanation of drawings]

The figure is a block diagram showing one embodiment of the stacking device of the present invention. In the figure, reference numbers 1 and 2 are register stacks, 11, 12, 21 and 22 are stack pointers, 3 is a main memory, 4 is an arithmetic operation unit, and 5 is a register stack.
and 6 indicate a register, and 7 indicates a control means, respectively.

Claims (1)

[Claims] 1 A plurality of register stacks consisting of multiple words and controlled in a last-in, first-out format, a main memory that stores data evicted from the register stack in a last-in, first-out format, and arithmetic processing. A unit and one job program use one of the register stacks.
When a job program is executed using one job program and a switch to another job program occurs, processing is performed using another register stack, and in parallel, the job program is accumulated in the register stack that has been used so far. What is claimed is: 1. A stack device comprising: control means for performing a process of expelling the stored data to the main memory, and efficiently changing register stacks when changing jobs.