JPS60230238A - Microprogram control device - Google Patents

Abstract

PURPOSE:To execute easily the patch of a micro-instruction and to optimize of the micro-instruction by rewriting a microprogram in a control memory by the micro-instruction. CONSTITUTION:A microprogram in a control memory 3 is rewritten by storing temporarily a data (microprogram) sent from a main memory through a bus 1, in a buffer memory 9 through a driver 2, and thereafter, transferring it to the control memory 3. That is to say, the store destination head address of the buffer memory 9, the transfer destination head address of the control memory 3, and the number of transfer data are loaded to registers 11, 12, and a transfer controlling circuit 10, respectively. When the transfer controlling circuit 10 is started, the data is transferred to the address of the control memory 3 indicated, by the register 12, and when a prescribed data transfer is ended, a multiplexer 13 inputs a data of an address controlling circuit 6 side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a microprogram control device for a computer controlled by a microprogram.

[Technical background of the invention]

The control memory devices in conventional microprogram control computers include a control memory that stores microprograms, and a WC8 (Wratable) memory that is open to the user.
Control Storage). Usually, the control memory is RO8 (ReadOnly S
In recent years, memory cards have been constructed using RAM because of the ease of batch processing of microprograms. If the control memory is configured with RAM, the floppy disk or EP
- The microprogram is initialized from the ROM to the RAM.

FIG. 1 is a block diagram showing an example of a conventional microprogram control device. Reference numeral 1 is a tistron bus, and reference numeral 2 is a driver used to take in data from this bus 1. Reference numeral 3 is a control memory in which basic microprograms (microinstructions) are stored, and reference numeral 4 is a writable control memory (WC) that is open to the user.
S).

Reference numeral 5 is a register (CDR) into which the microinstruction immediately before execution read from the control memory 3 or WO84 is loaded.
Reference numeral 6 is an address control circuit that decodes the microinstruction and reads out the next microinstruction to be executed from the control memory 3 or WO84. Reference numeral 7 is an address register (WAR) that holds an address sent from the destination bus 1, and reference numeral 8 is a multiplexer that selects an address from the address register 7 or the address control circuit 6.

If the control memory 3 is not configured with RO8, a floppy disk or separate ROM (not shown) will be inserted when the power is turned on.
The microinstructions are transferred from the control memory 3 to the control memory 3. Normal instructions (machine language) are executed by successively reading microinstructions stored in the control memory 3. The operation at this time is to read the microinstruction from the control memory 3 into the register 5, decode it, and control other circuits for executing the instruction. A part of the microinstruction held in the l/register is sent to the address control circuit 6 as address information.
is input to. The address control circuit 6 stores the address where the next microinstruction to be executed is stored in the control memory 3.
Or output to WO2 to access control memory 3.

The write operation to WO84 is performed as follows. That is, after loading the write address of wc S 4 to the register 7 through the destination bus 1 and driver 2, the multiplexer 8 is switched to select the register 7 side. After that, data (microinstruction) to be written to WC84 is sent to WO84 through destination bus 1 and driver 2, and from register 7 to multiplexer 8.
A microinstruction is written to the WO84 according to the address specified through the WO84.

The above operations are executed by microinstructions. At this time,
The data transmitted by the transmission bus 1 is mainly data from a main memory (not shown), and data is transferred from the main memory to the WO 84. In addition, W
□When executing the microinstruction on C8A, after setting the multiplexer 8 to the address control circuit 6 side and inhibiting the output of the control memory 3, the WO84 is executed according to the address output from the address control circuit 6 through the multiplexer 8.
The microinstruction within is read and loaded into register 5.

In this way, in conventional microprogram control devices, data can be rewritten by microinstructions themselves using W.
It was limited to O84 only. Therefore, the contents of the control memory 3 are not rewritten while the CPU is operating.1. ^
There wasn't. For this reason, microprograms have been patched by rewriting the contents of a floppy disk or EP-ROM.

[Problems with background technology]

As mentioned above, in the conventional microprogram control device,
It is only in WO2 that the microprogram can be rewritten while the CPU is operating, and it is not possible to rewrite the basic instruction microprogram stored in the control memory, so it is not possible to easily rewrite batches of microinstructions. However, the disadvantage is that it is not possible to perform dynamic optimization of microinstructions.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, an object of the present invention is to provide a microprogram control device in which microprograms can be telegraphed by microinstructions themselves.

[Summary of the invention]

The present invention provides a rewritable control memory for storing micro-instructions, a buffer memory for temporarily holding rewritten micro-instructions to be transferred to the control memory, and a transfer from the buffer memory to the control memory when activated by the micro-instructions. A transfer control circuit that controls data transfer, an address control circuit that holds the protruding address of a microinstruction to be executed after this data transfer, and controls the reading of the microinstruction from the control memory, and the minimum necessary level immediately after power is turned on. The above object q) is achieved by employing a microprogram control device comprising a memory for transferring a microprogram to the control memory and an initial transfer control circuit.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings, in which the same parts as those of the conventional example are given the same reference numerals. FIG. 2 is a block diagram showing one embodiment of the microprogram control device of the present invention. Reference numeral 1 is a destination bus, and reference numeral 2 is a driver used to take in data from this bus 1. Reference numeral 3 is a rewritable control memory (RAM) in which micro-instructions are stored, and reference numeral 5 is a register (CDR) into which the micro-instructions immediately before execution that are output from the control memory 3 are loaded. Reference numeral 6 is an address control circuit for the control memory 3. Reference numeral 9 is a buffer memory for temporarily storing data to be transferred to the control memory 3 via the destination bus 1. Reference numeral 10 is a buffer memory that is activated by a microinstruction and transfers the contents of the papier memory 9 to the control memory 3.
This is a transfer control circuit that controls the transfer to the buffer memory 9, and numeral 11 is a register (AR) that holds the read/write address of the buffer memory 9. Reference numeral 12 is a register (WAR) that holds the write address of the control memory 3 when data is transferred to the control memory 3, and reference numeral 13 is a register (WAR) that holds the write address of the control memory 3 when data is transferred to the control memory 3. When reading and executing this, a multiplexer (MPX) selects the address from the address control circuit 6 and outputs it to the control memory 3.
).

Reference numeral 14 denotes a memory (microprogram) for storing microinstructions (microprograms) to be transferred to the control memory 3 immediately after the power is turned on.
RO8), and reference numeral 15 indicates when the microinstruction from RO814 is transferred from RO814 to control memory 3.
14, an initial transfer control circuit that controls the control memory 3;

Next, the operation of this embodiment will be explained. When the power is turned on, microinstructions (microprograms) in the RO 814 are transferred to the control memory 3 by the initial transfer control circuit 15 and written in order. After this transfer is completed, the address control circuit 6
The microinstructions in the control memory 3 are read out and loaded into the register 5, and the microinstructions are sequentially executed.

That is, 1. Normal microinstruction execution is performed using register 5, address control circuit 6, multiplexer 13, and control memory 3.
, register 5) is controlled by a loop.

Next, we will explain how to rewrite the control memory 3. To rewrite the microprogram in the control memory 1, data (microprogram) sent from the main memory (not shown) through the destination bus 1 is first passed through the driver 2. This is done by loading the buffer memory 9 and then transferring the microprogram from the buffer memory 9 to the control memory 3. That is, the buffer memory 9 is transferred via the destination bus 1 in response to a microinstruction read from the control memory 3.
After setting the data storage destination address in the register 11 through the driver 2, the data (micro program) read from the main memory (not shown) is sequentially stored into the buffer memory 9 through the destination bus 1 and the driver 2 according to the storage destination address. . After this data transfer is completed, the storage destination start address of the buffer memory 9, the transfer destination start address of the control memory 3, and the number of transferred data are loaded into the register 11, the register 12, and the transfer control circuit 10, respectively. Next, the transfer control circuit 10 that controls data transfer from the buffer memory 9 to the control memory 3 is activated. When this activation occurs, the contents held in the data register 5 become invalid, and the address control circuit 6 holds the address of the microinstruction to be executed next to the activated microinstruction. Transfer control circuit 10 reads data from the address of buffer memory 9 indicated by register 11 and writes this data to the address of control memory 3 indicated by register 12. Buffer memory 9
When a predetermined amount of data has been transferred from the address control circuit 6 to the control memory 3, the multiplexer 13 is switched to take in the data from the address control circuit 6.
The microinstruction in the control memory 3 is read out according to the read address sent from the control memory 3, and is loaded into the register 5. At this time, the contents of register 5 become valid, and the aforementioned microinstruction is executed.

〔Effect of the invention〕

According to this embodiment, the control memory 3 is
The microprogram within the computer can be rewritten over its entire range, making it easy to patch microinstructions.Furthermore, the computer itself can dynamically change the microprogram, making it easy to optimize microinstructions. can be done. Furthermore, the control memory 3 has an area (WO2) where basic control data is stored, as well as an area (WO2) where data freely used by the user is stored.
By eliminating the boundaries between the basic control data storage area and the capacity of WO2, the efficiency of use of the control memory 3 can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional microprogram control device, and FIG. 2 is a block diagram showing an embodiment of the microprogram control device of the present invention. 3... Control memory 4.11.12... Register 6... Address control circuit 9... Buffer memory 10... Transfer control circuit 13... Multiplexer 14... Memory 15... Initial stage Transfer control circuit agent Patent attorney Kensuke Chika (and 1 other person)

Claims (1)

[Claims] a rewritable control memory that stores microinstructions;
A buffer memory that temporarily holds the rewriting microinstruction to be transferred to this control memory, a transfer control circuit that controls data transfer from the buffer memory to the control memory when activated by the microinstruction, and a transfer control circuit that controls the data transfer from the buffer memory to the control memory, and holds the read address of the microinstruction to
ε comprising an atrus control circuit that controls reading of microinstructions from the control memory, and a memory and an initial transfer control circuit that transfer the minimum required microprogram to the control memory immediately after power is turned on. microprogram controller.