JPS58159150A - Diagnosing device for control storage device - Google Patents

Abstract

PURPOSE:To facilitate the diagnosis of a control storage device, by comparing successively the microinstructions with those read out of a diagnosing storage device regardless of the executing order of the microinstructions within a microprogram sequence controller connected to a control storage comparing device. CONSTITUTION:A microprogram sequence controller 1 is connected with a control storage comparing device 9. In a diagnosis mode, the contents of an increment instruction register 6 are always delivered from a selector 7. The microinstruction of a designated address is read out to a microinstruction register 5 as well as to a diagnosing microinstruction register 11 and then compared at a comparator 12. When the comparison is over, 1 is added to an address register 4. Then the instruction of the next address position is read out of a control storage device 2 and a diagnosing control storage device 10 for comparison 12. The contents of the register 4 are set at the head address value 1 when they exceed the maximum address value of the device 2. Thus the diagnosis is carried out for all regions regardless of the executing order of microinstructions.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for diagnosing a control storage device that stores microprograms.

Conventionally, there has been no effective method for diagnosing control storage devices that store microprograms.

Therefore, it has been common practice to perform a parity error check on microinstructions read out according to the order of execution when the microprogram is actually executed.
By the way, micro-instructions include branch instructions, so in order to read and check all the micro-instructions stored in the control memory, a huge amount of simulation is required to consider the execution order of the micro-program. The disadvantage is that you have to prepare a program.

Furthermore, parity error checking has the disadvantage that if a plurality of bits are erroneous, it may not be detected as an error.

It is an object of the present invention to provide a diagnostic method capable of diagnosing all areas of a control storage device in a short time, regardless of the order of execution of microinstructions.

The diagnosis method for a control storage device according to the present invention combines a control storage comparison device with a microprogram sequence controller, and performs a control-storage comparison device in the microprogram sequence controller, regardless of the execution order of microinstructions. The microinstructions read out in address order are compared in sequence with the microinstructions read out from the diagnostic control storage device in the control storage comparator using the addresses sent from the microprogram sequence control device. It is characterized by diagnosing the storage device.

The figure is a block diagram showing an example of a rounding device that implements the diagnostic method according to the present invention.

In the figure, numeral 1 denotes a microprogram sequence control device for controlling the execution order of microprograms, and numeral 9 denotes a control storage and comparison device coupled to this /-g/s system # device 1. In the microprogera l sequence system device 1, 2 is a control storage device that stores a microprogram;
6 is a sequencer, 4 is an address register, and the sequencer 6 controls the contents of this address register 4. The contents of the address register 4 are input to the control storage device 2 as an address signal, and the microphone C1 command at the address position specified by the address signal is read out from the control storage device 2. 5 is a microinstruction register in which microinstructions read from the control storage device 2 are temporarily held.

6 is an increment instruction register, which is connected to address register 4, and sets the contents of address register 4 to the number 1.
, and holds a microinstruction for instructing an arithmetic control unit (not shown) to perform no operation. A selector 7 inputs the contents from the microinstruction register 5 and the increment instruction register 6, and selects and outputs one of them. In diagnostic mode,
This selector 7 is always increment instruction register 6
, and sends it to the decoder 8.

The decoder 8 decodes the input microinstruction, and in the diagnostic mode it decodes the contents from the increment instruction register 6, gives a no-operation command in the control code output to the arithmetic control section, and The signal output to address register 6 gives an increment instruction to increase the contents of address register 6 by one.

In the control storage comparator 9 that diagnoses the control storage device, 10 indicates that the correct microprogram is the control storage device 2.
This is a diagnostic control storage device that is stored in the same address order as the microprogram sequence control value flI, and receives the address signal sent from the address register 4 in the microprogram sequence control value flI as input, and the microinstruction at the address position specified by the address signal is Read out. A diagnostic microinstruction register 11 temporarily holds microinstructions read from the diagnostic control storage device 10, and takes in data at the same timing as the microinstruction register 5. 12 is a comparison circuit, and microprogram sequence control device 1
The contents of the microinstruction register 5 and the contents of the diagnostic microinstruction register 11 are compared.

The operation of the device configured in this way is as follows.
In the normal operation mode, the microinstructions read from the control storage device 2 are temporarily held in the microinstruction register 5, and the contents are given to the decoder 8 via the selector 7, which determines the execution order of the microprogram. Accordingly, the microinstructions are read from the control 41 storage 2 sequentially, and the presence of the incrementing instruction register 6 has no effect.

On the other hand, in the diagnostic mode, the contents of the increment instruction register 6 are always output from the selector 7, so
The microinstruction at the specified address is read into the microinstruction register 5 and the diagnostic microinstruction register 11, respectively, and the contents of the two are compared in the comparison circuit 12. When the comparison is completed, the value 1 is added to the contents of the address register 4, and the instruction at the next address location is read from the control storage 2 and the diagnostic control storage 10, respectively. When the contents of the address register 4 exceed the highest address value of the control storage device i12, the contents of the address register 4 are reset to the first address value 1 of the control storage device 2. Therefore, the execution order of microinstructions is Regardless, le 1
] The microinstructions stored in the control storage device 2 and the microinstructions stored in the diagnostic IIIJ#4I storage device mio are read out in address order and compared in the comparison circuit 12. If the comparison circuit 12 determines that the contents of the microinstruction register 5 and the contents of the diagnostic microinstruction register 11 do not match, the comparison circuit 12 outputs a signal indicating this, and the control storage device 2 is stopped for diagnosis. interrupt.

As described above, according to the present invention, all areas of the control storage device can be diagnosed in a short time regardless of the order of execution of microinstructions, which is effective in finding faults in the control storage device.

[Brief explanation of drawings]

The figure is a block diagram showing an example of a device for implementing the diagnostic method according to the present invention. 1... Micronorokuramnoken control device, 2.
...Control storage device, 6...7-kensa, 4.
・Address register, 5...Micro 6 command/
Star, 6... Increment instruction register, 7.
...Selector, 8...Decoder, 9...A
ll m memory comparison device, 10... control storage device for diagnosis, 11... micro-torque register for diagnosis, 1
2... Comparison circuit. Agent Haku Tameno −

Claims (1)

[Claims] (1) a control storage device that stores a microprogram made up of microinstructions, an address register that specifies the address of this control storage device, and a microinstruction register that holds microinstructions read from the control storage device; an increment instruction register that holds a microinstruction for instructing the contents of the address register to be sequentially increased by a numerical value of 1; a selector that switches and outputs the contents of the increment instruction register or the contents of the microinstruction register; a microprogram sequence control device comprising a decoder for decoding the internal information output from the selector; and a diagnostic control memory that stores the correct microprogram of the control memory and is supplied with an address signal output from the address register. a diagnostic microinstruction register for holding microinstructions read from the diagnostic control storage; and a comparator for comparing the contents of the diagnostic microinstruction register with the contents of the control microinstruction register. In the diagnostic mode, the selector outputs the contents of the increment command register, controls the contents of the address register to increase by a numerical value of 1, and controls the contents of the address register to increase by a value of 1. exceeds the highest address value of the control storage, the contents of the address register are reset to the starting address value of the control storage, and in the control storage comparison device, the comparison circuit compares the contents of the microinstruction register with the diagnostic A method for diagnosing a control storage device, the method comprising 1* diagnosing the control storage device by sequentially comparing the contents of a microinstruction register.