JPH05143387A - Diagnostic mechanism for microprogram - Google Patents

Abstract

PURPOSE:To obtain a microprogram diagnostic mechanism minimizing the number of auxiliary registers necessary for the diagnosis of a microprogram to be stored in a rewritable control storage device. CONSTITUTION:Codes corresponding to the addresses of a rewritable control storage (WCS) 5 at the rate of 1 to 1 are stored in the WCS 5 instead of a microprogram to be diagnosed, an auxiliary register group 60 is connected only to respective unit registers constituting a register group 6 connected to the data output of the WCS 5 and respective auxiliary registers 612 are connected like a chain. On the other hand, a diagnostic computer 1 for controlling the chain of the registers 612 is arranged on the outside of a status machine 50 and a microprogram to be diagnosed is stored in the computer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microprogram diagnostic mechanism. More specifically, it is a rewritable control storage device (WCS: Writable Control Store) provided in a state machine such as a computer or a control device. It relates to a diagnostic mechanism of a microprogram stored and controlling its state machine.

[0002]

2. Description of the Related Art In a state machine such as a computer or a control device, auxiliary registers capable of mutually exchanging the contents of various internal registers holding the internal state are arranged corresponding to the respective registers, and the auxiliary registers are chained. Conventionally known is a technique for reading or changing the internal state of the state machine by connecting the two in a state of parallel and shifting the contents of these auxiliary registers while reading out to the outside of the state machine. Such techniques are, for example, "Bipolar Microproces
sor Logic and Interface Data Book "(AdvancedMicro
Devices Company, 1985).

Normally, in this type of state machine, auxiliary registers are prepared for all the internal registers, and these auxiliary registers are connected in a chain. And
For example, when diagnosing a microprogram to be stored in WCS, the microprogram to be diagnosed is stored in WCS to cause the state machine to operate normally, and the contents of each internal register at that time are stored in the auxiliary register. By reading out to the outside of the machine and comparing it with a known normal state, it is diagnosed whether the micro program has a bug or whether the micro program itself is correctly described. ..

[0004]

By the way, in this type of conventional state machine, since auxiliary registers are prepared for all the internal registers, the area occupied by the auxiliary registers on the chip becomes large and the manufacturing cost is low. There is the problem of becoming expensive.

The present invention has been made in view of the above circumstances, and minimizes the number of auxiliary registers necessary for diagnosing a microprogram to be stored in a rewritable control storage device. Therefore, it is an object of the present invention to provide a microprogram diagnostic mechanism that solves the problems that the area occupied by the auxiliary register on the chip becomes large and the problems that the manufacturing cost becomes high.

[0006]

In the diagnostic mechanism of the microprogram of the present invention, WCS (rewritable control storage device) is used.
The code corresponding to the WCS address is stored in one-to-one instead of the microprogram to be diagnosed. WC
Since there are more data bits in S than there are address bits, it is possible to store such a code in WCS.

Auxiliary registers are provided only for each unit register that constitutes a register group connected to the data output of WCS, and these auxiliary registers are connected in a chain. On the other hand, a diagnostic computer for controlling a chain of auxiliary registers is provided outside the state machine, and a microprogram to be diagnosed is stored in this diagnostic computer.
Then, the clock for changing the state of the state machine is sequentially added to the state machine under the control of the diagnostic computer.

FIG. 1 is a block diagram showing the basic configuration of the diagnostic mechanism of the microprogram of the present invention. In FIG. 1, reference numeral 1 is a diagnostic computer, which holds a microprogram to be diagnosed during diagnosis. Reference numeral 50 is a state machine, which is provided with an instruction register 3, a sequencer 4, a WCS 5, a register group 6, and an auxiliary register 60 group provided corresponding to the register group 6.

Normally, the instruction register 3 sequentially holds each instruction of a program to be executed by the state machine 50. The sequencer 4 controls the microprogram stored in the WCS 5 according to each instruction held in the instruction register 3, and the instruction of each microprogram is output to each unit register constituting the register group 6 in bit divisions, and the instruction is output. Executed. The state change inside the state machine 50 at this time is stored in the status register 7. Conventionally, when diagnosing a microprogram, the WCS5 is made to hold the microprogram to be diagnosed, and the address of this WCS5 is designated by the instruction register 3 or the status register 7 etc.
To output the microprogram to the register group 6. Therefore, when diagnosing a conventional microprogram, it is necessary to use auxiliary registers that are also provided for the instruction register 3, the status register 7, and each unit register that constitutes the register group 6.

However, in the present invention, the microprogram to be diagnosed is held by the diagnostic computer 1, and the WCS 5 stores a code corresponding to the address on a one-to-one basis. As mentioned above, it is possible to store such a code, since WCS5 has more data bits than address bits.

Further, in the present invention, the auxiliary register group 60 in which the respective auxiliary registers are connected in a chain shape is provided only in the register group 6, and the contents thereof are controlled by the diagnostic computer 1 to cause the state machine 50. Read out of the. The clock for changing the state of the state machine 50 is sequentially given to the state machine 50 under the control of the diagnostic computer 1.

[0012]

The operation of the basic structure of the diagnostic mechanism of the microprogram of the present invention as shown in FIG. 1 is as follows.

First, the first microprogram instruction is set in the register group 6 from the diagnostic computer 1 through the auxiliary register group 60, and one pulse of the clock is added. After that, the address of the next instruction is instructed to the address terminal of WCS5.

As described above, the WCS5 address and 1
Since the code corresponding to the pair 1 is stored, the diagnostic computer 1 can know the next address of the microprogram by reading the code via the auxiliary register group 60. The microprogram instruction at the next address is executed by the same procedure. By repeating such a procedure, the trace of the microprogram to be diagnosed can be executed even if the contents of the instruction register 3 and the status register group 6 are not known.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments thereof.

FIG. 2 is a block diagram showing a concrete configuration example of an embodiment of the diagnosis mechanism of the microprogram according to the present invention.

In FIG. 2, reference numeral 50 is a state machine such as a computer or a control unit to which the microprogram diagnostic mechanism of the present invention is applied, and the diagnostic computer 1 is connected to the outside thereof. The diagnostic computer 1 is directly connected to the serial protocol control circuit 2 of the state machine 50. The serial protocol control circuit 2 is connected to the diagnostic computer 1 and the state machine 50 via the register group 6 with the auxiliary register. Controls the exchange of information with.

Reference numeral 3 is an instruction register, and the output of this instruction register 3 is given to the sequencer 4 via the multiplexer 10. The output of the sequencer 4 is a rewritable control storage device.
(Hereinafter referred to as WCS: Writable Control Store) 5, and the output of this WCS 5 is given to the register group 6 with an auxiliary register.

Reference numeral 7 is a status register,
The information representing the state of the state machine 50 given from the ALU 8 is stored. Reference numeral 9 is a FIFO (First In First Out) memory, the contents of which are written or read by the ALU 8.

A clock signal CLK is supplied to the instruction register 3, the sequencer 4 and the ALU 8, and their respective states change simultaneously in synchronization with this clock. The state of the register group 6 with the auxiliary register changes in synchronization with the clock signal PCLK. Both clock signals CLK, PCLK are controlled by the diagnostic computer 1 when the state machine 50 is in the diagnostic mode.

FIG. 3 is a block diagram showing the detailed structure of the register group 6 with auxiliary registers shown in FIG.
Reference numerals 61, 62, 63, and 64 respectively indicate unit registers of the register group 6 with auxiliary registers. The data D output from the WCS5 is input to each unit register 61, 62, 63, 64 with an auxiliary register. More specifically, for example
If the D terminal output from WCS5 is 24 bits, each unit register with auxiliary register 61, 62, 63, 64 has 8-bit structure.
1, 62, 63 divide and hold all bits of the WCS5 24-bit D terminal output in parallel. The unit register 64 with an auxiliary register holds the same bits as the unit register 62.

Reference numeral 65 is an AND gate for holding the clock PCLK input to the unit registers 61, 62, 63 and 64 with auxiliary registers in the unit register 64.
It is provided to prohibit input according to LD.

FIG. 4 is a block diagram showing the detailed structure of the unit registers 61, 62, 63, 64 with auxiliary registers described above. Reference numeral 611 indicates each unit register 61 of the register group 6,
62, 63 and 64 are main registers, and 612 is an auxiliary register 612 composed of a shift register.

Bits (for example, 8 bits obtained by dividing 24 bits into three equal parts) of the D terminal output of WCS5 are input to the main register 611, and output from the Q terminal as required. The auxiliary register 612 arranged corresponding to each main register 611 is configured to be able to take in and store the Q terminal output of this main register 611, and also to accept the input from the shift input SDI. Further, the auxiliary register 612 is configured so that the stored contents can be input to the main register 611 or can be output as a shift output SDO.

As shown in FIG. 3, the shift input SDI of the auxiliary register 612 of the unit register 63 with auxiliary register is set so that data is input from the diagnostic computer 1 via the serial protocol control circuit 2. And its shift output SDO is connected to the shift input SDI of the main register 611 of the unit register with auxiliary register 62. Further, the shift output SDO of the auxiliary register 612 of the unit register with auxiliary register 62 is connected to the shift input SDI of the main register 611 of the unit register with auxiliary register 61. And unit register 61 with auxiliary register
The shift output SDO of the auxiliary register 612 is output to the diagnostic computer 1 via the serial protocol control circuit 2.

The shift output SDO of the auxiliary register 612 of the unit register 63 with auxiliary register is also connected to the shift input SDI of the auxiliary register 612 of the unit register 64 with auxiliary register.

In the microprogram diagnostic mechanism of the present invention as described above, the microprogram to be diagnosed is loaded into WCS5, the register group 6 with the auxiliary register is set to the initial state, and the clock signal CLK and the clock signal PCLK are simultaneously set. You can change it. Here, the operation in the diagnostic mode in which the progress of the microprogram can be observed from the outside will be described.

In the WCS 5, first, a code is stored such that D = A, that is, the input data to the D terminal becomes the address output from the A terminal. The diagnostic computer 1 sets the initial state in the register group 6 with the auxiliary register via the serial protocol control circuit 2 and applies one pulse of the clock signal CLK. Since the WCS5 is set as described above, the next microinstruction address is designated to the D terminal of the WCS5. The diagnostic computer 1 reads the value via the serial protocol control circuit 2 and the register group 6 with the auxiliary register. This procedure will be described in detail below.

When one pulse of the clock signal PCLK is applied, the data from the D terminal of WCS5 is set in each unit register 61, 62, 63, 64 which constitutes the register group 6 with the auxiliary register. The value set in each unit register 61, 62, 63, 64 is transferred to each auxiliary register 612 provided corresponding to each unit register 61, 62, 63, 64, and the chain of auxiliary registers is shifted. By doing so, data is obtained.

However, at this time, the output of the register group 6 changes. Therefore, as long as the clock signal CLK is not applied,
There is no effect on the synchronous signal, but if an asynchronous signal such as the read signal FR of the FIFO memory 9 changes, a side effect will occur. As shown in FIG. 3, the asynchronous signal auxiliary register-equipped register group 6 has a dual configuration, and
The unit register 62 for reading input and the unit register 64 for Q output are separated. The conversion of the clock signal PCLK of the unit register 64 is prohibited by the hold signal HOLD when reading the D input. This leaves the asynchronous signal unchanged.

The diagnostic computer 1 shifts the read micro-instruction at the next address into the auxiliary register of the register group 6 with the auxiliary register via the serial protocol control circuit 2. Then, release the hold signal HOLD
By applying one pulse of PCLK, the contents of the auxiliary register are transferred to the register group. The above procedure is repeated.

[0032]

As described above in detail, in the microprogram diagnostic mechanism of the present invention, since the auxiliary register is provided only in the register group which receives the output of the rewritable control storage device, the auxiliary register is provided on the chip. The occupied area can be suppressed and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a diagnostic mechanism for a microprogram according to the present invention.

FIG. 2 is a block diagram showing a specific configuration example of an embodiment of a microprogram diagnosis mechanism according to the present invention.

FIG. 3 is a block diagram showing a detailed configuration of a register group with auxiliary registers shown in FIG.

FIG. 4 is a block diagram showing a detailed configuration of each unit register.

[Explanation of symbols]

 1 Diagnostic computer 5 WCS 6 Register group 50 State machine 60 Auxiliary register group 61, 62, 63, 64 Unit register 611 Main register 612 Auxiliary register

Claims (1)

[Claims] 1. A diagnostic mechanism for a microprogram of a state machine, which operates by a microprogram stored in a rewritable control storage device having more data bits than address bits, comprising a plurality of bits of the control storage device. The storage contents can be mutually exchanged between a register group composed of a plurality of registers for dividing the output data and storing the shift data, and each register of the register group can be connected in a chain shape and the shift register as a whole. A group of auxiliary registers composed of a plurality of auxiliary registers functioning as an external register, and a microprogram to be diagnosed, which is held outside the state machine. At the time of diagnosis, the microprogram to be diagnosed is based on data output from the control storage device. A code capable of specifying the address of the And a code output from the control storage device to the register group is transferred to an auxiliary register connected in a chain, and further, the auxiliary register is shifted to be output outside the state machine to read the next address. And a diagnostic control unit having means for shifting and inputting a microinstruction of the address to the auxiliary register, and further setting it in the register group from the auxiliary register. ..