JPH01204145A - Microprogram controller - Google Patents

Abstract

PURPOSE:To attain a branch operation even through no deciding nor branching instruction into a microinstruction program by using hardware to set a jumping destination address and to perform the jumping control. CONSTITUTION:A jumping destination address is set at a 1st register, an address to be compared with an executing address is set at a 2nd register 2, and the execution control is set at a branch control circuit 4 for the comparison jump. The microinstruction for the executing address outputted from a microaddress counter 5 is read out of a microprogram and carried out. Then the circuit 4 loads the value of the register 1 into the counter 5 when the coincidence is obtained between the executing address and the value of contents of the register 2. The microprogram is jumped to the value shown by the register 1. Thus it is possible to perform a branch operation even though the deciding and branching instructions are not written into the microinstruction program.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a microprogram control circuit for an information processing device based on a microprogram system.

(Prior Art) Conventionally, in this type of microprogram control type information processing device, if you want to branch a microprogram, you write a judgment instruction at the location where you want the branch to occur, and then jump just in case the replacement conditions match. It was configured like this.

FIG. 8 is a flowchart showing the flow of a processing program in the microprogram control device according to the prior art. From processing 1 to processing 5? If you don't do it,
Judgment order? Need to run 5 times.

(Problems to be Solved by the Invention) In the above-mentioned conventional microprogram control device, a decision instruction for branching and a jump instruction must be written in advance at the location where the branch is desired, and the number of instructions is also limited. Make sure to execute the decision instruction even if there is no need to increase and branch.

An object of the present invention is to solve the above-mentioned drawbacks by setting the jump destination address and controlling the jump using hardware.
It is an object of the present invention to provide a microprogram control device configured to be able to perform branching without having to write instructions for determination and branching into a microinstruction program.

(Means for Solving Section !!) A microprogram control device according to the present invention includes first and second register means, a microaddress counter, a comparison means, and a branch control means. It is an accomplishment.

The first register means is for holding a jump destination address, and the second register means is for holding data to be compared with the execution address of the microprogram.

The micro address counter is for indicating the execution address of the micro program.

The comparison means is for comparing the contents of the second register means and the output of the microaddress counter.

The branch control means is intended to set the contents of the first register means to the microaddress counter when the comparison result by the comparison means indicates a match.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a microprogram control device according to the present invention. # In figure 41,
1 and 2 are registers, 3 is a comparator, 4 is a branch control circuit, S is a micro address counter, and 6 is a control storage device.

Set the jump destination address in the first register 1, and
The address to be compared with the execution address is set as data in the register 2, and the execution control of the comparison jump is set in the branch control circuit 4. Then, the microprogram is run. Microinstructions at execution addresses are read from the microprogram and executed one after another. If the execution address and the value of the contents of the second register 2 match, the branch control circuit 4 loads the value of the first register 1 into the microaddress counter 5 and transfers the microprogram to the first register.
jump to the value indicated by register 1 of

In the circuit described above, register 2 of nest 2 is accessible by the microprogram with a width equal to the number of addresses to the storage device in which the microprogram resides.

FIG. 2 is a flowchart showing the flow of the processing program in the microprogram control room 1 shown in FIG. According to the present invention, processes 1 to 5 can be executed without using a determination instruction.

(Effects of the Invention) As explained above, the present invention allows determination and branching instructions to be written in a microinstruction program by setting a jump destination address and performing the jump *uh't in advance. The structure can be configured so that all branches can be executed even without the use of a microprogram, and the execution time for the determination instruction is shortened and the execution speed of the microprogram can be increased.

[Brief explanation of the drawing]

FIG. 1 is a block diagram partially illustrating one embodiment of a microprogram control circuit according to the present invention. FIG. 2 is a flowchart showing an example of processing in the microprogram control device of FIG. Is Fig. 3 a microprogram based on conventional technology? l11
It is a flowchart which shows the example of a process in a visit clear. 1...Register 2@e time register 3...Ratio/Articulator 4...Φ branch control circuit 51111/Micro address counter 6...Control note 1i! Device

Claims (1)

[Claims] a first register means for holding a jump destination address; a second register means for holding data to be compared with an execution address of the microprogram; and a microaddress counter for indicating the execution address of the microprogram. and a comparison means for comparing the contents of the second register means and the output of the microaddress counter, and when the comparison result by the comparison means indicates a match, the output of the microaddress counter is A microprogram control device comprising branch control means for setting the contents of the first register means.