JPH0342756A - Command processor - Google Patents

Abstract

PURPOSE:To speedily abolish a command stored in a queue in an error state by providing a command discrimination part discriminating whether the command is to be executed or abolished and a status discrimination part discriminating a command execution state. CONSTITUTION:When the command 6 comes to be the error and the flag of a status 7 is returned when the command 6 is executed in a command execution part 3, the status discrimination part 5 discriminates that the command execution part 3 is in the middle of the error. Then, the instruction of command abolishment is transmitted to the command discrimination part 3 and the status 7 is stored in a status queue 2. The next command 6 is prevented from being given to the execution part 3 and is abolished by taking out the subsequent command 6 from a command queue 1 and discriminating in the command discrimination part 5 and giving the instruction of command abolishment. The command 6 is abolished until a master processor 9 reads the status in the middle of the error and it stops issuing the command.

Description

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

rPrior art] Conventionally, this type of command processing device has a command queue that sequentially stores commands issued asynchronously from a higher-level processor, and a command execution unit that periodically extracts commands from the command queue, executes them, and returns a status. , and a status key that sequentially stores the status from the command execution unit, and the commands issued from the upper processor are executed by the command execution unit as many as are stored in the command queue, regardless of the status from the command execution unit. are doing.

[Problem that the invention seeks to solve]

In the conventional command processing device described above, the commands stored in the command queue are periodically executed by the command execution unit regardless of the reports from the command execution unit. Even if the status is returned from the command execution unit, only the amount stored in the command queue is passed to the command execution unit, and there is a problem in that the command execution unit returns a status indicating that the command execution unit is in error.

(Means for Solving the Problems) The Hacomant processing device of the present invention is a command processing device that processes commands issued by a higher-level processor and returns status; a command determining unit that periodically extracts a command from the command queue and determines whether to execute, discard, discard, or release the command; and execute a command determined to be executed by the command determining unit. a command execution unit that returns a report; determines whether or not the command execution unit is in error based on the status from the command execution unit; if the command execution unit is in error, sends a command to the command determination unit; It is provided with a status determining section that instructs discarding, and a status key that sequentially stores the status determined by the status determining section.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

Referring to FIG. 1 showing an embodiment of the present invention, a host processor 9 and a command processing device 8 are connected by a processor bus 10, and the command processing device 8 has a command key capable of storing four commands 6. 1,! :, a command discriminating unit 4 which extracts command 6 from command queue 1 and determines whether command 6 is a command indicating cancellation of discarding and whether to discard or execute the command; and a command execution unit which executes command 6 and returns status 7. 3 and command execution unit 3
The status determination unit 5 determines whether or not the command execution unit 3 is in error based on the status 7 from the command execution unit 3 and instructs the command determination unit 4 to discard the command if the command execution unit 3 is in error. and a status queue 2 that sequentially stores four subsequent statuses 7.

Figure 2 shows command 6 and status 7 in the same example.
The format of command 6 is command code 1.
It consists of a total of 8 bytes: 1 byte, 1 byte for the command discard/release flag, and 6 bytes for the information section. The status 7 consists of 1 byte of status code, 1 byte of flag indicating that the command execution unit 3 is in error, and 6 bytes of information part, 8 bytes in total.

Next, to explain the operation with reference to FIGS. 1 and 2, when the command execution unit 3 is normal, the command queue 1 is sequentially
command 6 is executed and status 7 is reported via status queue 2.

Here, when command 6 is executed by the command execution unit 3, an error state occurs and the flag of status 7 is returned as '01 dark blue.The status determination unit 5 determines that the command execution unit 3 is in error, and the command An instruction to discard the command is transmitted to the discriminator 3, and the status 7 is stored in the status queue 2.

The next command 6 is taken out from the command queue 1 and discriminated by the command discriminator 4, and since an instruction to discard the command has been issued, the command 6 is not passed to the command execution unit 3 and is discarded. The command 6 is discarded by the command discriminator 4 when the upper processor 9 reads the error status and stops issuing the command. Next, the upper processor 9 issues a command with the discard status release flag of command 6 as u01, and when the command is taken out from the command queue 1, the command discriminator 4 reads the command discard status release flag -Q I I/. The instruction to discard the command is canceled, and the command 6 is passed to the command execution unit 3 again.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a command determining unit that periodically extracts a command from a command queue and determines whether the command execution unit discards or executes the command in an error state, discards the command, or cancels discarding the command; By providing a status determination section that determines whether or not the command execution section is in error based on the status from the execution section, and instructs the command determination section to discard the command if the command execution section is in error. If the command execution section enters an error state,
Commands already stored in the command queue can be discarded without causing the error status to be sent to the upper processor many times.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing the format of commands and status in the same embodiment. 1...Command queue 2...Status queue 3...Command execution part, 4...
・Command discrimination section, 5...Status discrimination section,
6...Command, 7...Status,
8...Command processing device, 9...Upper processor, 10...Processor bus.

Claims (1)

[Claims] A command processing device that processes commands issued by an upper processor and returns status; a command queue that sequentially stores commands issued asynchronously from the upper processor; and a command queue that periodically extracts and executes commands from the command queue. a command determination unit that determines whether to discard, be discarded, or cancel discard; a command execution unit that executes a command determined to be executed by the command determination unit and returns a report; and a status from the command execution unit. to determine whether or not the command execution unit is in error, and if the command execution unit is in error,
A command processing device comprising: a status determining unit that instructs the command determining unit to discard a command; and a status queue that sequentially stores statuses determined by the status determining unit.