JPS6127775B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information processing device using a microprogram control method.

When the number of bits required for microcontrol differs depending on each step of microprogram control type information processing equipment, the following method has conventionally been used.

A method that adjusts the number of bits per microinstruction to the step that requires the maximum number of bits for microcontrol.

In order to carry out microcontrol by setting the number of bits per microinstruction as n, a method uses hardware to control all the steps that are insufficient with n bits or to control the missing bits.

However, with the above method, the capacity of the storage device in which microinstructions are stored becomes larger than necessary.
The disadvantage of this method was that the expandability and flexibility of the control method was reduced.

An object of the present invention is to provide a microprogram control system that can reduce the capacity of a storage device in which microinstructions are stored without relying on a hardware control method when the number of bits required for microcontrol is different for each step of microcontrol. The goal is to provide equipment.

To achieve the above object, a microprogram control device according to the present invention includes a storage device in which microinstructions are stored, a control register for reading and holding microinstructions stored in this storage device, and a control register having a bit length of 1 micron. a stack consisting of one or more registers shorter than the bit length of an instruction; means for storing information in the control register in the stack according to instructions from the microinstruction; a step for controlling a controlled circuit according to instructions and information in the stack, and a surplus portion of the steps that can control the controlled circuit with a number of bits less than the number of bits per microinstruction is stored in the stack. death,
In a step where the number of bits per microinstruction is insufficient, the insufficient number of bits is read from the stack to perform microcontrol.

According to the above configuration, the object of the present invention can be completely achieved.

An embodiment of the present invention will be described below with reference to the drawings.

The figure is a block diagram showing one embodiment of a microprogram control device according to the present invention.

In the figure, an arithmetic circuit 1, which is a controlled circuit, has three arithmetic blocks 2 and 3, each of which can be controlled independently.
and 4, and the microinstructions that control the arithmetic circuit 1 are each composed of a 1-word long first microword, a second microword, and 3 control bits, and are used to control each arithmetic block. Assume that a microword of one word length is required.

The control store 5 is a storage device that stores microinstructions, and the microinstruction at the address specified by the read address 30 is read from the control store 5 and set in the control register 6.

Address register 7 is a register that sets the result of adding 1 to read address 30 by adder 9, and the next read address (current read address + 1) other than when branching is sequentially set. The switching circuit 8 is a circuit for selecting an address to be used as the read address 30, and when selecting the address register 7, the read address is set to an address that is +1 to the read address one step before.
The control register 6 is selected when the microinstruction set in the control register 6 is a branch microinstruction and the branch destination address is a read address.

The control bit of the microinstruction set in the control register 6 for controlling the arithmetic circuit 1 is sent to the decoder 10 via the signal line 31, and the first microword is sent to the switching circuits 11, 19 and 20 via the signal line 32. The two microwords are transmitted via signal line 33 to switching circuits 11 and 20 and to decoder 23.

The switching circuit 11 is the first one of the control register 6.
The second microword and the second microword are selected by the decoder 10 and transmitted to the stack 12.

Stack 12 consists of four registers 13, 14, 15 and 16, each one word wide. Counter 17 is a 2-bit counter that indicates which register among the four registers of stack 12 is to be set with the micro word output from switching circuit 11, and counter 18 is
This is a 2-bit counter indicating from which of the four registers the microword is read and sent to the switching circuits 19 and 20. counter 1
When 7 and 18 are both “00”, register 1
3, register 14 when "01", register 15 when "10", register 1 when "11"
6 is selected and incremented by +1 by the control signal from the decoder 10. The switching circuit 19 selects the microword in the stack 12 and the first microword in the control register 6 according to instructions from the decoder 10 and sends them to the decoder 21. The switching circuit 20 is connected to the stack 12
microword inside and the first of control register 6
The microword and the second microword are selected according to instructions from the decoder 10 and sent to the decoder 22.

Decoders 21, 22, and 23 correspond to calculation blocks 2, 3, and 4, respectively. When the control signal from decoder 10 is an on signal, decoder 21 receives the output of switching circuit 19, and decoder 22 receives the output of switching circuit 20. The decoder 23 decodes the second microword of the control register 6 to control the arithmetic blocks 2, 3 and 4, and does not control the arithmetic blocks when the control signal from the decoder 10 is an off signal.

The decoder 10 decodes the 3 control bits of the microinstruction set in the control register 6 and decodes the switching circuits 11, 19 and 20, the stack 12, the counters 17 and 18, and the decoder 2.
1, 22, and 23 to perform control as shown below.

(Control bit) (Contents of control) 000...Instructs the switching circuit 19 to select the first micro word and the switching circuit 20 to select the second micro word, sends an on signal to decoders 21 and 22, and an off signal to decoder 23. .

001...Instructs the switching circuit 19 to select the first microword, and sends an on signal to decoders 21 and 23 and an off signal to decoder 22.

010...Instructs the switching circuit 20 to select the first microword, and sends an on signal to the decoders 22 and 23 and an off signal to the decoder 21.

011...Instructs the switching circuit 11 to select the second microword, sends a set signal to the register of the stack 12 indicated by the counter 17, and increments the contents of the counter 17 by 1. It also instructs the switching circuit 19 to select the first microword and sends an on signal to the decoder 21 and an off signal to the decoders 22 and 23.

100...Instructs the switching circuit 11 to select the second microword, sends a set signal to the register of the stack 12 indicated by the counter 17, and increments the contents of the counter 17 by 1. It also instructs the switching circuit 20 to select the first microword and sends an on signal to the decoder 22 and an off signal to the decoders 21 and 23.

101...Instructs the switching circuit 11 to select the first microword, sends a set signal to the register of the stack 12 indicated by the counter 17, and increments the counter 17 by 1.

It also sends an on signal to the decoder 23 and an off signal to the decoders 21 and 22.

110...Reads the micro word from the register of the stack 12 indicated by the counter 18 and increments the contents of the counter 18 by 1. Also, the switching circuit 19
The switching circuit 20 instructs the switching circuit 20 to select the first microword read out from the stack 12, and sends an ON signal to the decoders 21, 22 and 23.

111...Reads the microword from the register of the stack 12 indicated by the counter 18 and increments the contents of the counter 18 by 1. Also, the switching circuit 19
It instructs the switching circuit 20 to select the first microword in the stack 12 and sends an ON signal to the decoders 21, 22 and 23.

In other words, in the step where the control bit is "000", the first micro word causes the operation block 2 to be
However, the calculation block 3 is controlled by the second microword.

In the step where the control bit is "001", the first microword controls the arithmetic block 2, and the second microword controls the arithmetic block 4.

In the step where the control bit is "010", the first microword controls the arithmetic block 3, and the second microword controls the arithmetic block 4.

In the step where the control bit is "011", the first microword controls the arithmetic block 2, the second microword is set in the register of the stack 12 indicated by the counter 17, and
The contents of the counter 17 are incremented by 1.

In the step where the control bit is "100", the first
Arithmetic block 3 is controlled by the micro word,
The second microword is set in the register of stack 12 indicated by counter 17, and the contents of counter 17 are incremented by one.

In the step where the control bit is "101", the operation block 4 is controlled by the second microword, and the first
The microword is stack 1 indicated by counter 17.
2 register and counter 1
The contents of 7 are increased by +1.

In the step where the control bit is "110", the micro word read from the register of the stack 12 indicated by the counter 18 causes the arithmetic block 2 to
The first microword causes the calculation block 3 to
The arithmetic block 4 is controlled by the micro word and the contents of the counter 18 are incremented by one. At the step where the control bit is "111", the counter 18
The microword read from the register of the stack 12, indicated by , controls the arithmetic block 3, the first microword controls the arithmetic block 2, and the second microword controls the arithmetic block 4. The contents of 18 are incremented by +1.

As explained above, the present invention stores in the stack the extra part of the steps that can be controlled with fewer bits than the number of bits per microinstruction, and stores the extra part of the steps that can be controlled with the number of bits less than the number of bits per microinstruction. Since the microcontroller can perform microcontrol by reading out the data from the stack, it has the effect of reducing the capacity of the control store.

Furthermore, the problem of deterioration in expandability and flexibility of the control method described in the conventional example does not occur.

[Brief explanation of the drawing]

The figure is a block diagram showing one embodiment of a microprogram control device according to the present invention. 1... Arithmetic circuit (controlled circuit), 2, 3, 4... Arithmetic block, 5... Control store (storage device), 6... Control register, 7... Address register, 8, 11, 19, 20... Switching circuit, 9
...Adder, 10, 21, 22, 23...Decoder,
12...Stack, 13, 14, 15, 16...Register, 17, 18...Counter.

Claims (1)

[Claims] 1 A stack consisting of a storage device in which microinstructions are stored, a control register that reads and holds microinstructions stored in this storage device, and one or more registers whose bit length is shorter than the bit length of one microinstruction. a means for storing information in the control register in the stack according to instructions from the microinstruction; and means for storing information in the control register in the stack according to instructions from the microinstruction in the control register; The remaining steps that can control the controlled circuit with fewer bits than the number of bits per microinstruction are stored in the stack, and the remaining steps that can control the controlled circuit with fewer bits per microinstruction are stored in the stack. A microprogram control device configured to perform microcontrol by reading the missing number of bits from the stack.