JPS63188239A - Microprogram controller - Google Patents

Abstract

PURPOSE:To early detect errors for improvement of reliability with a microprogram control device by reading all words loaded in a control memory at the time of initialization and then checking errors. CONSTITUTION:The titled controller is provided with a scan read control circuit 7 which resets an increment register 3 by an external start signal (scan read instruction signal) and fixes an address switching circuit 4 at the side of the register 3. Then the data on all words stored in a control memory 1 are successively read out and if a correctable error is detected, it is corrected by an error detecting/correcting circuit 6. Thus the memory 1 is rewritten by a corrected microinstruction. Then it is possible to check whether the data are loaded correctly into the memory 1 or not. As a result, the reliability of a microprogram controller is improved.

Description

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

In particular, it relates to a method for detecting errors in data loaded into control memory during initialization.

[Conventional technology]

Conventionally, in a microprogram control device, data (program) is written into a control memory at the time of initial setting, and control is performed based on this data.

At this time, the data loaded into the control memory is not checked to see if it has been loaded correctly.

[Problem that the invention seeks to solve]

As mentioned above, conventional microprogram control devices do not read all words of data loaded into the control memory during initial setup to detect errors, so even if there is an error in the loaded data, it will not be detected during device operation. After the data has been read.

There is a problem in that the error is discovered for the first time.

[Failure to solve the problem]

The microprogram control device of the present invention includes a control memory for storing microinstructions, a microinstruction register in which data read from the control memory is set, and an error correction code for the microinstructions stored in the control memory. an error detection and correction circuit that performs error detection and correction based on the contents set in the microinstruction register, and sets the corrected microinstruction in the control memory and the microinstruction register;
an adder circuit that adds 1 to the address of the control memory;
an increment register that holds the output of the adder circuit; and an address switching circuit that switches a part of the contents of the microinstruction register and the contents of the increment register as an address of the control memory; Scan read means is provided which resets the increment register by a start signal and fixes the address switching circuit to the increment register side, and sequentially reads data i of all words loaded into the control memory to detect a correctable error. When the microinstruction is corrected, the microinstruction is corrected and the control memory is rewritten with the corrected microinstruction.

〔Example〕

The present invention will be explained below with reference to Examples.

FIG. 1 is a block diagram showing one embodiment of the present invention. Referring to FIG. 1, the microprogram control device includes a control memory 1. Microinstruction register 2, increment register 3. Switching circuit 4. Addition circuit 5. Error detection and correction circuit 6. and a scan read control circuit 7.

The control memory 1 that stores a plurality of microinstructions is connected to the connection 10.
1 and is connected to the microinstruction register 2. A part (some bits) of the microinstruction register 2 indicates the address of the control memory 1 where the microinstruction to be executed next is stored, and is connected to the switching circuit 4 by a connection 102. All bits of microinstruction register 2 are connected to wire 103
The output of the error detection and correction circuit 6 is connected to the control memory 1 and the microinstruction register 2 by a connection 104. The output of the increment register 3 is connected to the address switching circuit 4 through a connection 105, and the address switching circuit 4 switches between part of the contents of the microinstruction register 2 and the contents of the increment register 3.

The output of the address switching circuit 4 is connected via a connection 106 to the control memory 1 as the address of the control memory 1, and is also connected to the adder circuit 5. The adder circuit 5 has a function of adding 1 to the output of the address switching circuit 4, and is connected to the increment register 3 through a connection 107. and,
Increment register 3 is being read from control memory 1! = Holds the value plus the address end of the microinstruction.

External start signal (scan read instruction signal) When the scan read control circuit 7 is instructed to perform a scan read,
The scan read control circuit 7 resets the increment register 3 regardless of the instruction of the microinstruction, and instructs the address switching circuit 4 to select data in the increment register 3.

As a result, the addresses of control memory 1 are sequentially +
It is added by 1 and read out. The read data of the control memory 1 is set in the microinstruction register 2, and an error correction code is given to the microinstruction by the error detection and correction circuit 6, and the microinstruction is checked for errors. When a correctable error is detected by the error detection and correction circuit 6, the error detection and correction circuit 6 performs the correction and connects the control memory l via the connection 104.
and rewrites the contents of microinstruction register 2.

〔Effect of the invention〕

As described above, in the present invention, by reading all words of data loaded into the control memory at the time of initial setting and checking for errors, it is possible to detect errors at an early stage, and this has the effect of improving reliability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. 1... Control memory, 2... Micro instruction register. 3... Increment register, 4... Address switching circuit, 5... Addition circuit, 6... Error detection and correction circuit. 7...Scan read control circuit. Jump 1 figure

Claims (1)

[Claims] 1. A control memory for storing microinstructions, a microinstruction register in which data read from the control memory is set, and an error correction code is assigned to and stored in the microinstructions stored in the control memory. an error detection and correction circuit that detects and corrects errors based on the contents set in the microinstruction register and sets the corrected microinstructions in the control memory and the microinstruction register; and an error detection and correction circuit that adds 1 to the address of the control memory. an increment register that holds the output of the adder circuit; and an address switching circuit that switches between a part of the contents of the microinstruction register and the contents of the increment register to set the address of the control memory. In the control information processing device,
Scan read means is provided for resetting the increment register by an external activation signal and fixing the address switching circuit to the increment register side, and sequentially reads data of all words loaded into the control memory to detect and correct errors. A microprogram control device characterized in that when an error is detected, the error is corrected and the control memory is rewritten with the corrected microinstruction.