JPS6177942A - Microprogram controller - Google Patents

Abstract

PURPOSE:To facilitate an easy inspecting job of a microprogram and an easy changing job of the program contents by executing and passing repetitively an optional range of a microprogram stored in a memory. CONSTITUTION:A sequencer 5 delivers a microaddress 6 of a microcode 1 of a step following a microprogram under execution based on an address control code included in the code 1. Here an address monitor circuit 11 monitors the address 6 delivered from the sequencer 5 and delivers a jump command signal 14 when the coincidence is obtained between the address 6 and the address of the jump side. An address changing circuit 12 receives the signal 14 and changes the address 6 into an address of the jump receiver side which is set previously. This address is sent to an input line 13 of a microprogram memory 4. Thus the microprogram is executed as shown in a figure (a) or (b).

Description

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

"Prior art" The central processing unit (CP[J) of a computer is a ROM
(read-only memory) and RAM (random access memory) are connected to the pass line, and ROM
It executes various operations while reading the instructions written in the .

This instruction is decoded inside the CP port, replaced with a sequence of a plurality of microinstructions (microprogram), and executed.

To distinguish between instructions manually input to the CPU and microinstructions, the former are called macroinstructions.

For example, a macro instruction is manually input to the CPU at one system clock (here, the lock executed by the macro instruction is called the system clock) cycle, but in a microprogram, for example, one macro instruction is input, and the next macro instruction is input manually. The execution completes by the time the Therefore, if the microprogram has 16 steps, for example, one microinstruction is executed within 1/16 of the system clock.

Such a microprogram is the internal CI of the CPU.
It is stored in the ROM provided in J (control device).

FIG. 5 shows an example of the configuration of the microcode, and FIG. 6 shows a block diagram of a circuit for executing the microcode.

In FIG. 5, the microcode 1 is composed of, for example, a 9-bit microinstruction 2, a 4-bit address control code 3, and various other codes (not shown) as necessary.

The microprogram execution circuit shown in FIG. 6 includes a microprogram memory 4 in which a necessary number of microprograms consisting of a series of microcodes are stored in the order of microcode addresses (microaddresses), and a microprogram memory 4 that stores microprograms consisting of a series of microcodes in the order of microcode addresses (microaddresses). It has a micro sequencer 5 that controls the operation of taking out the . The microprogram is executed as follows. first,
When the microsequencer 5 specifies the microaddress 6 of the microcode 1 to be output first, the first microcode 1 is outputted from the microprogram memory 4. The microinstruction 2 of the microcode 1 is output to the ALU (arithmetic logic unit) of σPtJ.

On the other hand, the address control code 3 of the microcode 1 is sent back to the microsequencer 5, and the microsequencer 5 outputs the microaddress 6 of the microcode 1 of the next step based on this address control code 3.

In this way, the sequence of the microprograms is determined by the address control code 3 contained in the microcode 1 along with the microinstructions 2, and when one microprogram starts, the processing of the last microcode starts. The microprogram is executed automatically until the fishing is completed.

"Problem to be Solved by the Invention" In such a microprogram control device, for the purpose of program debugging, etc., it is necessary to repeatedly execute a specific range of one microprogram and check its operation. Work may be required.

Conventionally, this type of inspection work involves rewriting and executing the contents of a ROM containing a microprogram each time, or
The equipment was equipped with a dedicated large-scale debugger.

However, rewriting the microprogram requires a lot of time and is extremely inefficient. Furthermore, the use of a debugger or the like requires extensive work, and is not suitable for on-site inspection work for maintenance of equipment that is already in use.

The present invention has been made with attention to the above points, and an object of the present invention is to provide a microprogram control device that allows easy inspection of microprograms.

"Means for Solving Problems" The microprogram control device of the present invention performs the following operations based on a microprogram memory that stores a microprogram and an address control code included in the microcode output from the microprogram memory. A micro sequencer that outputs the micro address of the microcode of the step, and an address that sets the jump source address of the microprogram, monitors the micro address, and outputs a jump command signal when this and the jump source address match. The address changing circuit receives a jump command signal from the address monitoring circuit and changes the microaddress to a preset jump destination address.

In this microprogram control device, when a microaddress equal to the jump destination address set by the address monitoring circuit is output from the microsequencer, the microaddress is forcibly changed to the jump destination address set in advance by the address change circuit. This makes it possible, for example, to form an infinite loop in any range of a microprogram and check it. It is also possible to make any range of microprograms available on the bus.

The address monitoring circuit sets the jump destination address 1
Alternatively, it is preferable that the address changing circuit has one or more dip switches for setting a jump destination address.

If such a dip switch is attached to the microprogram control device, the dip switch can be switched whenever it is necessary to check various ranges of the program.

It would also be possible to create two or more arbitrary loops,
The address setting circuit or the address changing circuit may be provided with a jump command signal canceling circuit. This makes it possible to cancel the infinite loop, etc., without having to cancel the jump destination address or the set value of the jump destination address, not only after the inspection is completed but also during the inspection.

Embodiment FIG. 1 is a block diagram of a basic embodiment of the microprogram control device of the present invention.

This device includes a microprogram memory 4, a microsequencer 5, an address monitoring circuit 11, and an address changing circuit 12. The microprogram memory 4 is formed of, for example, a ROM, stores various microprograms consisting of a series of microcodes, and outputs the corresponding microcode 1 when a microaddress is entered manually from the manual line 13. This microcode 1 includes an address control code 3 and a microinstruction 2.

The microsequencer 5 outputs the microaddress 6 of the microcode 1 of the next step of the microprogram being executed based on the address control code 3 included in the microcode 1.

If the address control code 3 is the same signal as the micro address 6 of the micro program memory 40, the micro sequencer 5 latches the address control code 3 and outputs it as is at the next timing. If the micro address 6 is a part of the address control code 3 with a predetermined signal added, the micro sequencer 5 outputs the micro address after that processing.

The address monitoring circuit 11 includes a circuit for setting a jump destination address in advance. Address setting circuit 11
monitors the microaddress 6 output by the microsequencer 5, and outputs a jump command signal 14 when this and the jump destination address match. When the address change circuit 12 receives this jump command signal 14, it changes the micro address 6 to a preset jump destination address and sends it to the input line 13 of the micro program memory.

As a result, the microprogram is executed as shown in FIG. 2 or 3.

2 and 3 show a microprogram consisting of 12 steps 31-312, each step e.g.
l means execution of one microinstruction.

In FIG. 2, this program is 312 in order from Sl.
However, since the jump destination address A is specified by the address monitoring circuit 11 shown in FIG. 1 and the jump destination address B is specified by the address change circuit 12, the program is After execution from step S1 to SIO, the process returns to step S4, and thereafter an infinite loop is formed in which the microinstructions from step S4 to step 510 are repeatedly executed.

In FIG. 3, as in FIG. 2, a jump source address A and a jump destination address B are set, but their positional relationship is reversed. Therefore, this microprogram is executed from step S1 to step S4, then jumps to step S10, and ends at step 312. That is, in the case of FIG. 3, the settings are made when it is desired to pass steps S5 to S9. Also,
For example, as shown by the broken line arrows in FIG. 2, two or more jump destination addresses C and jump destination addresses D may be specified to form a complicated loop or the like as necessary.

Settings as shown in FIG. 2 are performed from step S4 to step SI.
This is effective for checking whether the microprogram execution up to O is normal, and the settings as shown in Figure 3 are
If the execution of the microprogram from step S5 to step S9 is excluded, it is effective for checking whether a predetermined operation is performed or not.

Such inspection processing can be easily performed using, for example, a two-phenomenon synchroscope. Furthermore, if a part of a system using this device breaks down, all microprograms related to the faulty part can be passed, thereby avoiding stopping the entire system.

FIG. 4 is a block diagram of a more specific embodiment of the microprogram control device of the present invention.

In this device, the microsequencer 5 is composed of an address register 20 and a branch circuit 21. Further, the address monitoring circuit 11 is composed of a dip switch 23, a comparison circuit 24, an AND circuit 25, and a jump command signal canceling circuit 34, and the address change circuit 12 is composed of a dip switch 26 and a selector circuit 27. The jump command signal canceling circuit 34 includes a switch 35 having one end grounded and the other end connected to one of the input terminals of the AND circuit 25.

This device operates as follows.

When the address control code 3 is output from the microprogram memory 4 to the microsequencer 5, its upper bits are directly input to the address register 20, and the lower bits are input to the branch circuit 21, for example. Branch circuit 2
1, when a branch condition 22 is input from an external device such as an ALU, the lower bits of the address control code 3 are changed according to the condition.

The address register 20 latches the microaddress finally determined in this way and outputs it at a predetermined timing. This timing is controlled by a clock 36 that is input to the address register 20 via a tarlock generation circuit 30 and a synchronization circuit 31 that synchronizes its clock with the system clock of the macro instruction.

In the address monitoring circuit 11, the dip switch 23
Set the jump destination address in advance. In the figure, 4-bit address data is input to the comparator circuit 240 input terminal Q.
is man-powered. The micro address 6 previously output from the micro sequencer 5 is input to the other input terminal P of the comparison circuit 24 . When these two addresses match, the output 32 of the comparison circuit 24 becomes "H". When the switch 35 is turned off as shown in the figure, the AND circuit 25
If the other terminal 33 is set to "H'", the output 14 of the AND circuit 25 becomes "H".

On the other hand, in the address change circuit 12, if a jump destination address is set in the dip switch 26, the jump destination address is input to the selector circuit 270 input terminal R, and the jump destination address is output from the microsequencer 5 to the other input terminal S. Micro address 6 is input. Selector circuit 2
When an "H" signal is manually input to the control terminal SS of the microprogram memory 4, the selector circuit 27 inputs the jump destination address manually input to the input terminal R to the input line 13 of the microprogram memory 4.
Output to.

If the input to the comparison circuit 24 of the address monitoring circuit 11 does not match the jump destination address, the output 14 of the AND circuit 25 becomes "L" and the selector circuit 27 directly stores the micro address 6 output from the micro sequencer 5 in the micro program memory. Output for 4.

Note that when the switch 35 of the address monitoring circuit 11 is turned on, the input terminal 33 of the AND circuit 25 is always "L", and even if the output 32 from the comparison circuit 24 is "L", it is "H".
”, the output of the AND circuit 25 becomes “L”. Therefore,
The address change circuit does not substantially operate. Furthermore, a similar operation can be achieved even if a switch is provided to ground the control terminal SS of the selector circuit 27 of the address change circuit 12.

If the address monitoring circuit and address change circuit are equipped with dip switches for specifying the jump destination address and the jump destination address, as in the embodiment shown in this figure, it will be possible to use this device even in the field where this device is actually used. ,
Inspection work can be easily performed without bringing special debugging equipment. Of course, the DIP switch, the address monitoring circuit, and the address changing circuit themselves may be separately assembled using devices having similar functions and attached externally on an emergency basis.

Further, when providing a plurality of jump destination addresses or jump destination addresses, two or more dip switches or the like may be appropriately added using the same principle.

Furthermore, if there is a jump command signal cancellation function, it is not only possible to prevent the operation of these circuits when the device is in operation, but also to change the operation of the microprogram when used in combination with each DIP switch, making it highly useful. .

"Effects of the Invention" The microprogram control device of the present invention described above has the following features:
It is possible to repeatedly execute or pass any range of microprograms stored in microprogram memory, making it easy to inspect microprograms and change the contents of microprograms, making it very practical. It is of high value.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a basic embodiment of the microprogram control device of the present invention, FIGS. 2 and 3 are explanatory diagrams of the order of execution of microprograms by the device of the present invention, and FIG. 4 is a block diagram of a basic embodiment of the microprogram control device of the present invention. FIG. 5 is a block diagram of a specific embodiment, FIG. 5 is a microcode configuration diagram suitable for implementing the present invention, and FIG. 6 is a block diagram of a conventional microprogram control device. 1...Microcode, 2...Microinstruction, 3...
... Address control code, 4 ... Micro program memory, 5 ... Micro sequencer, 6 ... Micro address, 11 ... Address monitoring circuit, 12 ...Address change circuit, 23.26...Dip switch, 34...
...Jump command signal cancellation circuit. Applicant: Fuji Xerox Co., Ltd. Representative
Patent Attorney Ume Yu Yamauchi 1st
Figure 2 Figure 3

Claims (1)

[Claims] 1. A microprogram memory that stores a microprogram, and a microprogram that outputs the microaddress of the next step microcode based on the address control code included in the microcode output from the microprogram memory. a sequencer, an address monitoring circuit that sets a jump source address for the microprogram, monitors the microaddress, and outputs a jump command signal when the microaddress matches the jump source address; and a jump command for the address monitoring circuit. A microprogram control device comprising: an address changing circuit that receives a signal and changes the microaddress to a preset jump destination address. 2. A microprogram characterized in that the address monitoring circuit has one or more dip switches for setting a jump source address, and the address changing circuit has one or two or more dip switches for setting a jump destination address. Control device. 3. The microprogram control device according to claim 1 or 2, wherein the address monitoring circuit or the address changing circuit has a jump command signal canceling circuit.