JPS6330938A - Microprogram control device - Google Patents

Abstract

PURPOSE:To increase processing speed, by enabling a micro-operation designated by a specific field executed at just prior step to be repeated, by setting a specific bit being outputted by a control code memory. CONSTITUTION:A code selector 2 is used to set the output of a recursive code register 3 itself executed at the just prior step, at the recursive code register 3. The control of the code selector 2 is performed by using a designation bit 21 which designates the designation of a recursive micro-operation outputted by the control code memory 1, and the code selector 2 selects the output of the control code memory 1 when the designation bit 21 is reset, and sets it at the recursive code register 3, but, when the designation bit 21 is set, it selects the output of the recursive code register 3 itself, and sets it as its own register. In this way, the micro-operation executed at the just prior step is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microprogram control device that controls a microprogram written in microinstructions and has a function of re-executing a microoperation executed in the immediately previous step.

[Conventional technology]

As research into knowledge information processing progresses, the functions required of computer systems also become more sophisticated. for example,
One of these is unification processing, which is a basic function of the programming language Prolog, which is attracting attention in the field of knowledge information processing.

The microprogram control method, which is widely used as a means for realizing computer systems, is suitable for realizing the above-mentioned advanced functions. Improving the functionality of a computer system using a microprogram control method means converting the functions that were realized by software in conventional general-purpose computer systems into microprograms. Since the microprogramming of advanced functions increases the amount of microprograms and complicates the structure, there is a tendency to subdivide them into a large number of functional routines and adopt a structure in which the main routine calls the functional routines.

In order to call a functional routine, it is necessary to exchange data between the main routine and the functional routine. This is where data is stored for main routines and functional routines (
This is because the registers or specific addresses in memory are different.

One of the conventional techniques for realizing data reception and passing between a main routine and a functional routine is a method in which a register to be used for data reception and passing is specified.

In this method, the main routine must set data in a specified register immediately before calling the function routine. This method is called the first conventional technique.

Another conventional technique is a method in which the main routine passes the designated number of the register holding data to the functional routine. In this method, a register is specified for receiving and passing a designated register number, and when a functional routine accesses data, register access or memory access is performed by register indirect designation. FIG. 3 shows the case of register indirect specification register access. 1 is a control code memory that stores the microprogram, and 10 is a microcode register (MCR) that holds the microinstruction being processed.
It is. The main routine uses the microcode register 10 to directly specify registers in the register file 13 and access data. When calling a function routine, a register designation number is set in the register 11 for indirect designation. In the functional routine, the indirect designation register 11 is used to designate a register in the register file 13 and access data. In this method, the main routine needs to set the register designation number to the specified register immediately before calling the function routine. This method is called the second conventional technique.

[Problem that the invention seeks to solve]

In the conventional technology, which used data transfer between the main routine and the function routine to realize a function routine call, the main routine always inputs data or a register specification number to a specific register group immediately before calling the function routine. I needed to set it up.

The operations set in specific registers by the main routine must be performed on all data received and passed between the main routine and the functional routines.

When using the prior art, the main routine's set operations on specific registers often increase the number of execution steps of the microprogram. Among these are:
Pass to function routine like unification processing 2
In some cases, one function routine is selected from a plurality of function routines using the results of the comparison with the data of , and a branch is made to that function routine. In the case of processing that uses data passed to a functional routine in the step that calls the functional routine, the setting operation of specific registers by the main routine, which was performed in the conventional technology, increases the number of execution steps of the microprogram and reduces the processing speed of the entire computer system. There is a problem with letting it happen.

An object of the present invention is to control the execution of a microprogram written using a microinstruction that has a specific bit that specifies re-execution of a microoperation specified by a specific field of a microinstruction executed in the previous step. Data exchange between function routines is a microprocessor that solves the problem of an increase in the number of microprogram execution steps in processing that uses data passed to a function routine in the step of calling a function routine, as seen in unification processing. The purpose of the present invention is to provide a program control device.

[Means for solving problems]

The microprogram control device of the present invention includes a control code memory for storing a microprogram, a repeatable code register for holding specific fields of a microinstruction, and a control code memory for storing a microprogram.
Field 3 other than the specific field of the microinstruction
The output code of the control code memory or the repeatable code register is selected depending on the value of a specific bit output by the non-repeatable code register held and the control code memory, and the selected code is repeatable. and a code operator that supplies the code register to the code register, and is configured to enable repetition of the micro-operation specified by the specific field executed in the previous step by setting the specific bit output from the control code memory. be done.

[Effect]

The microprogram control device of the present invention includes a repeatable code register that holds a code for a specific field of a microinstruction, and a code transition selector that selects an input of the repeatable code register from a control code memory and an output of the repeatable code register itself. If a specific bit of a microinstruction output by the control code memory is set, the repeatable code register re-holds its own output so that the specific bit executed in the previous step is Enables re-execution of the micro-operation specified by the field.

Some of the micro-operations performed in the step where the main routine called the functional routine? By re-running
Functional routines can directly manipulate data that is passed to and from the main routine. For example, in the case of unification processing, the processing contents differ depending on the combination of data types of two pieces of data exchanged between the main routine and the functional routine. In this example, in the step of calling a function routine, the main routine checks the combination of data types of the two data types, determines one function routine from a plurality of function routines based on the combination of data types, and Jump to function routine. Therefore, in the first step of the function routine, by re-executing the micro-operation specifying the access to the two data that was performed in the previous step (the step where the main routine called the function routine), the access to the two data can be performed. can be done. For example, if a register holds the above two pieces of data, the functional routine can store the above two pieces of data by re-executing the micro-operation that specifies the register.
data can be accessed.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a format diagram of microinstructions processed by the embodiment of the microprogram control device of the present invention which will now be described. 21 is for selecting either re-execution of the micro-operation specified by the specific field of the micro-instruction executed in the previous step or execution of the micro-operation specified by the specific field of the micro-instruction executed in the relevant step. This is a specified bit. Reference numeral 22 is a repeatable code field (RMC) that specifies a micro-operation that allows the re-execution of the micro-operation executed in the previous step using the specification bit 21. 20 is the specified bit 2
This is a non-repeatable code field (NMC) that specifies a micro-operation that cannot be re-executed in the immediately previous step.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, l is a control code memory that stores a microprogram. 3 is a repeatable code register that holds the repeatable code field of the microinstruction read from the control code memory 1;

4 is a non-repeatable code register that holds a non-repeatable code field of the microinstruction read from the control code memory 1;

In conventional microprogram controllers, it is not possible to re-execute the micro-operation executed in the previous step, so there is no bit in the micro-instruction that specifies the re-execution of a repeatable micro-operation. There is no distinction between regular code fields and non-repeatable code fields. That is, conventional microprogram controllers provide the same control over all fields of a microinstruction as a non-repeatable code field.

When selecting a micro-operation executed in the immediately previous step as a repeatable micro-operation, the repeatable code register 3 holds the repeatable code field used in the immediately previous step. The non-repeatable code field is held in the non-repeatable code register 4.

The code selector 2 is used to set the repeatable code register 3 to the output of the repeatable code register 3 itself that was executed in the previous step.

The code selector 2 is controlled using a designation bit 21 that designates a repeatable micro-operation of the microinstruction output by the control code memory 1, and the designation bit 21 of the code selector 2 is reset. At times, the output of the control code memory 1 is selected and set in the repeatable code register 3, but when the designation bit 21 is set, the output of the repeatable code register 3 itself is selected and set to the repeatable code register 3. This causes the micro-operation executed in the previous step to be repeated.

(Effects of the Invention) In the microprogram control device of the present invention, the repeatable code 3 that controlled the repeatable micro-operation executed in the immediately previous step is transferred back to the repeatable code register, and By making it possible to re-execute repeatable micro-operations executed in 1-, data exchange and passing between the main routine and functional routines as seen in the unification processing example can be realized by re-executing register-specified micro-operations. This has the effect of preventing an increase in the number of microprogram execution steps due to the P!Ii function routine call and improving the processing speed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a format diagram of microinstructions controlled by the microprogram control device of the present invention, and FIG. 3 is a block diagram of a conventional microprogram control device. . 1. Control code memory, 2. Code selection machine, 3.
- Repeatable code register (RMCR), 4... Non-repeatable code register (NMCR), 10... Microcode register (MCR>, 11... Indirect specification register, 12... Register specification number selector, 13...
・Register file, 20... Non-repeatable code field, 21... Specification bit)-122... Repeatable code field. $ / Figure 2

Claims (1)

[Claims] a control code memory that stores a microprogram; a repeatable code register that holds a specific field of a microinstruction; a non-repeatable code register that holds fields other than the specific field of the microinstruction; and a control code memory that stores a specific field that the control code memory outputs. a code selector that selects one of the output code of the control code memory and the output code of the repeatable code register according to a value of a bit, and supplies the selected code to the repeatable code register; A microprogram control device characterized in that by setting the specific bit output by the microprogram control device, it is possible to repeat the micro-operation specified by the specific field executed in the previous step.