JP2633382B2 - Multi-register file system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-register file system having a plurality of register files, and more particularly to a hardware configuration of register files.

(Conventional technology) In general, an architecture with a plurality of register files can avoid saving registers in the stack area, not only reduce overhead, but also easily improve interrupt responsiveness because register saving operations become unnecessary. It has been adopted in many systems because of its advantages. The number of data registers, address registers, or general-purpose registers constituting the register file depends on the operating system (hereinafter referred to as an operating system).
The amount that can be used in the system task executed by the OS) or the user task executed by the user application is equivalently implemented as hardware in each register file, and each register file has a symmetric configuration.

In the multi-register file system configured as described above, the task to be executed is switched for each register file because the register file is switched at the time of context and a new task or interrupt processing is executed with the new register file. Even if the program changes, the compiler can be generated uniformly by keeping the register configuration the same, and there is an advantage that variables in the program can be assigned to registers without restriction.

(Problems to be Solved by the Invention) However, in the above-described multi-register file system, the burden of providing all registers as hardware is large, and when a part of the registers is used as a working register, it is particularly necessary to save / restore the data when context switching. There was no need to save, and there was no need to provide all the registers that make up the register file.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and minimizes the burden of providing a register file as hardware in a multi-register file system, and can uniformly generate object code by assigning variables to registers by a compiler. The purpose is to provide a register file structure.

(Means for Solving the Problems) Means taken by the present invention to achieve the above object are as follows.

The invention according to claim 1 has a shared register file that does not belong to a specific task other than an occupied register file that each task individually has, and the shared register file specifies a register number that specifies a register, and thereby a system task is specified. , Data can be written from any task, regardless of whether it is a user task.

(Operation) With this configuration, the burden of implementing the register file as hardware can be minimized, and since the register configuration is common to each register file, the compiler can be generated uniformly and multi-tasking processing can be realized more efficiently. can do.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an example of a register file configuration for mounting a register file that does not belong to a specific task in the present invention.

The privileged register file 5 and the user register files 6, 7, and 8 are registers a1 to a8 and registers b1 to b, respectively.
8, registers c1 to c8, and registers d1 to d8.
８8 is equivalent. If the task to be executed by the task group 10 is an OS, the privilege register file 5 is selected, and if the task is a user task, any one of the user register files 6, 7, 8 is selected.

On the other hand, for the task-specific register files 5 to 8, the shared register file 9 independent of the privileged register file 5 and the user register files 6, 7, 8 is selected independently of the task to be executed by the task group 10. This shared register file 9 is composed of registers x9 to x12. For example, if the task to be executed by the task group 10 is an OS, the registers a1 to a8 of the selected privileged register file 5 and the registers Register x9 ~
x12 is such that register numbers indicating memory space addresses of registers are consecutive, and the OS uses 12 registers with registers a1 to a8 and registers x9 to x12 as registers 1 to 12. The same applies to each of the user register files 6, 7, and 8, and 12 registers are used in addition to the registers x9 to x12 of the shared register file 9.

Since the privilege register file 5 and the user register files 6, 7, and 8 are independent of each other, data is saved at the time of task switching, but since the shared register file 9 is common to the task group 10, When switching tasks, the data becomes invalid and is not saved. However, working variables can be arranged in registers by allocating the shared register file 9 by a compiler for working.

The number of registers constituting each of the register files 5 to 9 is eight or four, but is arbitrary. The bit width is also arbitrary according to the data register, address register or general-purpose register.

FIG. 2 is a block diagram of the multi-register file system of the present invention. The configuration of the present invention based on FIG. 2 when a shared register file not belonging to a specific task is implemented will be described together with the operation of register selection. .

The register files 11 to 14 are privileged or user register files, and are exclusively occupied by tasks. Reference numeral 15 denotes a shared register file independent of each task. First
The selection circuit 16 receives a register file number 18 specifying one of the register files 11 to 14, and selects the register file 11 to 14. On the other hand, the second selection circuit 17 receives the register number 19 for selecting which register in the register files 11 to 15 is input, and selects the corresponding register. In the register files 11 to 14, the registers selected by the first selection circuit 16 and the second selection circuit 17 are selected, and the registers of the shared register file 15 are selected only by the second selection circuit 17.

(Effect of the Invention) As described above, according to the present invention, the burden of providing a register file as hardware can be minimized, and a large number of register files can be implemented, so that multitasking processing can be efficiently realized. it can. In addition, a working variable of a task can be assigned to a register, and a high-level language-oriented compiler can easily assign a variable to a register, so that the efficiency of object code generation can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a register file for mounting a register file which does not belong to a specific task of the present invention, and FIG. 2 is a block diagram of a multi-register file system of the present invention. 5 ... Privileged register file, 6,7,8 ... User register file, 9,15 ... Shared register file, 10 ...
Task group, 11-14 ... Register file.

Claims (1)

(57) [Claims] 1. A multi-register file system comprising a plurality of register files, wherein each task implements a plurality of register files constituted by data registers, address registers or general-purpose registers which can be individually occupied. A shared register file that is constituted by a data register, an address register, or a general-purpose register and does not belong to a specific task is mounted, and data is written into the shared register file from any task by specifying a register number that specifies a register. A multi-register file system, characterized in that: