JPH01209533A - Microprogram controller - Google Patents

Abstract

PURPOSE:To improve the availability of the storage capacity by storing the data on an arithmetic control field also into a sequence control field with an address which receives an access only when the function of a decoder is secured. CONSTITUTION:A host control memory 1 stores a higher rank program and works and a selector control flip-flop 10 holds a specific bit of the memory 1. Then the flip-flop 10 controls a selector 7 with the output and selects the field of a control memory 4. Then, to an address which receives an access only when the function of a decoder of the memory 1 is secured in the memory 4, the next address field of the memory 4 and the part of a sequence control field are used as the control field of an arithmetic circuit 9 for storage of data. The field of said control field is selected by the specific bit of the memory 1 and sent to the circuit 9. In such a way, the capacity of the memory 4 can be applied effectively.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a microprogram control device.

In particular, the present invention relates to a microprogram control device having a function of operating a control memory as a decoder of a higher-level control memory.

[Conventional technology]

Conventionally, in microprogram control devices.

There is a control storage system in which the control storage used can also be accessed as a decoder using data in a specific field of the upper control storage.

[Problem to be solved by the invention]

However, according to the conventional control storage method mentioned above.

In the case of control by a microprogram, the sequence control is performed by the data of the next address field and the data of the sequence control field in the control memory, but when it is accessed as a decoder from the upper control memory, and For addresses in control storage that are only accessed, the contents of the next address field or sequence control field are not used and are wasted.

[Means to solve the problem]

The microprogram control device of the present invention has a control memory that stores a microprogram and has a sequence control function itself and is also accessed as a decoder by data in a specific field of an upper control memory, The area is divided into a sequence control field and other arithmetic control fields, and when operating via a sequence control circuit, the arithmetic circuit is controlled by the arithmetic control field, sequence control is performed by the sequence control field, and as a decoder. For addresses that are operated and accessed only when operating as a decoder, the data of the arithmetic control field is also stored in the sequence control field, and the sequence control is performed using specific bits of the field of the upper control memory. The present invention is characterized in that the output of a field or an arithmetic control field is selected to control the arithmetic circuit.

〔Example〕

Next, a microprogram control device according to the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In this figure, a higher-level control memory 1 stores and operates higher-level microprograms. In this control memory 1,
Data in a specific field in the microinstruction field is read out to the decoder register 2, and further accessed via the address selector 3 to the control memory 4 as a decoder.

The control memory 4 itself stores microprograms. Then, after the address from the address register 5 or the address from the next address field of the control memory 4 is selected in the sequence control circuit 6 based on the data from the sequence control field, the control memory 4 is accessed via the address selector 3. . Data read from control memory 4 is selected by selector 7 and held in read register 8, and an arithmetic circuit 9 is controlled by this output. Note that the selector control flip-flop 10 holds a specific bit of the upper control memory 1, and controls the selector 7 based on its output to select a field of the control memory 4.

FIG. 2 is a diagram for explaining the contents of the control memory 4.

In this figure, + a + C is the calculation control field,
b and d are sequence control fields. address l
Microprograms are stored from n-1. Of these, calculation control data is stored in a, and sequence control data is stored in b. Also, address n to m
These areas are accessed only as a decoder from the higher-level control memory 1, and therefore, arithmetic control data is stored in both areas.

When accessing the control memory 4 as a decoder from the upper control memory 1, areas a from addresses I to n-1 and areas c+d from addresses n to m are used as data for the decoder register 2 and selector control flip-flop 10. do. The output of the decoder register 2 passes through the address selector 3 to access addresses I to m of the control memory 4.

The selector control flip-flop 10 controls the selector and selects a,
Of area c, or area d.

Choose one. As a result, the control memory 4 from the upper control memory 1 is controlled as a decoder, and the a area from I to n-1 of the control memory 4 and the end from address n to m are controlled.
It becomes possible to use the data in the area as decoded output.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, for an address in the control memory that is accessed only as a decoder of the upper control memory, the next address field and sequence control field portion of the control memory are processed by an arithmetic circuit. This is highly effective in that the capacity of the control memory can be used effectively by storing data as a control field, selecting the field using a specific bit of the upper control memory, and sending this to the arithmetic circuit.

[Brief explanation of the drawing]

Figure 1 is a professional diagram showing the configuration of an embodiment of the present invention;
The figure is a diagram for explaining the contents of the control memory 4. 1... Upper control memory, 2... Decoder register, 3
...Address register, 4...Control memory, 5...
Address register, 6... Sequence control circuit, 7.
...Selector, 8...Read register, 9...Arithmetic circuit. Figure 1

Claims (1)

[Claims] 1. It has a control memory that stores microprograms, has a sequence control function by itself, and is also accessed as a decoder by data in a specific field of an upper control memory, and the storage area of the control memory is used as a sequence control field. Separated from other calculation control fields,
When operating via a sequence control circuit, the arithmetic circuit is controlled by the arithmetic control field, sequence control is performed by the sequence control field, and when operating as a decoder, an address that is accessed only when operating as a decoder. , the data of the arithmetic control field is also stored in the sequence control field, and the output of the sequence control field or the arithmetic control field is selected with a specific bit of the field of the upper control storage to control the arithmetic circuit. A microprogram control device characterized by: