JPH0462093B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a microprogram control processing method, and more specifically, by providing dedicated hardware, specific processing (input/output control processing) can be performed in addition to the main processing. ).

(Prior Art) Conventionally, a processing device that employs a microprogram control method performs input/output control including channels by controlling specific input/output devices, in addition to command processing as the main processing. The amount of hardware in the device has been drastically reduced, making it cheaper and smaller.

As described above, there are the following two methods for performing specific processing in parallel with the main processing.

One method is to check at an appropriate timing while the microprogram is performing its main processing to see if there is a request for specific processing, and if there is a request, to perform that processing.

The other is that the microprogram “updates the value” of a dedicated counter while performing its main processing.
This is a method in which "determination of count zero or overflow" is performed at appropriate time intervals, and specific processing is performed when the count is zero or overflow.

(Problem to be Solved by the Invention) However, in conventional microprogram control method devices, no matter which of the above two methods is adopted, extra microsteps are required to switch from main processing to specific processing. As a result, a problem arises in that processing overhead occurs. Furthermore, since it is necessary to incorporate operations for specific processing into the main processing, there is also the drawback that design becomes difficult.

Therefore, it is an object of the present invention to provide a microprogram control processing method that eliminates the processing overhead of the conventional devices described above, can efficiently execute specific processing, and can also reduce the difficulty in designing. .

(Means for Solving the Problems) In order to achieve the above object, the microprogram control processing method of the present invention is such that a microprogram corresponding to an input/output control instruction stored in a main memory is stored in a system for one control time. It is divided into a plurality of stages of a size that can maintain the required performance or service, and also has a processing content identification register and a timer. The processing content identification register stores data identifying the processing content, and this data can be set (written) and read by a microprogram. The timer can be set and started counting by a microprogram, and can cause an interrupt to the microprogram upon timeout.

(Function) According to the present invention, since the microprogram control processing method is configured as described above, it functions as follows.

When performing another specific process in addition to the main process, a timer is set in the microprogram, starts counting, and when the timer times out, the process is scheduled from the main process to the microprogram corresponding to the input/output control instruction. , the stage selected based on the contents of the processing content identification register is executed, and when the execution of that stage is finished, information on the next stage to be processed is set in the processing content identification register, and a predetermined timeout value is set in the timer. and start up and return to main processing. By repeating this process a predetermined number of times, the specific process is performed between the main processes. Therefore, there is no processing overhead, and specific processing can be performed efficiently, thereby solving the problems of the prior art.

(Example) An example of the present invention will be described below in detail based on the accompanying drawings. FIG. 1 is a block diagram showing the configuration of a microprogram control processing method according to an embodiment of the present invention, FIG. 2 is a diagram showing temporal changes in microprogram processing as a specific example, and FIG. 2 is an operational flowchart of microprogram processing.

In Figure 1, 11 is a central processing unit (hereinafter referred to as
12 is a main memory (hereinafter referred to as MEM), 13 is a bus, 14 is an input/output control circuit (hereinafter referred to as IOC), 15 is a timer, 16 is a processing content identification register, 17 is an input/output device (hereinafter referred to as IO ). The CPU 11 is connected to the MEM 12, and also to the IOC 14, timer 15, and processing content identification register 16 via a bus 13 that can be controlled by a microprogram. Also IOC14
is connected to IO17.

In this embodiment, the CPU 11 mainly executes instructions stored in the MEM 12,
These processes are performed with the specific process of controlling the input/output operations of the IO 17 that performs direct memory access. IOC14 consists of a simple circuit
It controls the operation of IO17, but IO
The operation of the CPU 17 is controlled based on instructions from a microprogram of the CPU 11. On the other hand, timer 1
5 is a hardware device that can be configured and instructed to start counting using the CPU 11 microphone and program.
It is a timer and can interrupt the microprogram upon timeout. The processing content identification register 16 is a register in which a value for identifying the processing content can be set and read by the microprogram of the CPU 11.

Next, the operation of this embodiment will be explained.

The input/output control operation consists of several stages (l)~
(n), but if these are processed continuously, the main processing will be interrupted for a long time, resulting in a decrease in the performance of the system. Therefore, Figures 2 and 3
As shown in the figure, input/output control operations are subdivided into multiple stages, and each control time is short enough to maintain the required performance of the system.
The CPU 11 schedules control of these subdivided IOs 17 in order between instruction processing.

First, the CPU 11 controls the input/output operations of the IO 17 by taking out input/output instructions from the MEM 12. As a result, the microprogram performs the startup operation of the IO 17, generates a condition code, and also sets the processing content identification register 16 to a value indicating that "startup processing is over and transfer preparation processing (part 1) will be performed next."('2') is input, the timer 15 is initialized and starts counting, and the process returns to the main processing (1 in FIGS. 2 and 3).
After this, when the timer 15 times out while the CPU 11 is executing the main processing (point a in Figure 2), the microprogram interrupt signal supplied from the timer 15 to the CPU 11 interrupts the instruction being executed. Once completed, input/output control operation (timer interrupt processing) begins again. Here, the microprogram first determines the value ('2') of the processing content identification register 16, performs the process determined by that value ('2'), and then updates this value for the next time. (set to '3'), the timer 15 is initialized and a count start instruction is given, and the process returns to the main processing (2 in FIGS. 2 and 3). By repeating the above procedure, in this example, the input/output command for IO17 is executed by CPU11 for input/output control (specific processing) n times.
This is achieved by performing this in between the main processing.

(Effects of the Invention) As described in detail above, according to the present invention, by having simple hardware such as a dedicated register and a timer, processing overhead can be eliminated and processing that was previously executed can be performed. In addition to (the main process), other specific processes can be executed easily and efficiently. Further, unlike the prior art, there is no need to incorporate operations for specific processing into previous processing, so there is an advantage that design is easy.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of an embodiment of the present invention, Fig. 2 is a time chart showing the temporal processing of microprogram processing as a specific example, and Fig. 3 is a flowchart of microprogram processing operation of specific processing. be. 11... Central control unit (CPU), 12... Main memory device (MEM), 13... Bus, 14... Input/output control circuit (IOC), 15... Timer, 16...
Processing content identification register, 17...Input/output device (IO).

Claims (1)

[Claims] 1. A register 16 that can be written/read from a microprogram, and a hardware timer 1 that can be activated from a microprogram.
In the microprogram control processing method for scheduling processing, the microprogram corresponding to the input/output control instructions stored in the main storage device 12 is configured to perform one control time according to the performance required for the system or Multiple stages ((1) to (n)) large enough to maintain service
When the hardware timer times out, processing shifts from the main processing to the microprogram corresponding to the input/output control instruction, the stage selected based on the contents of the register is executed, and the stage selected based on the contents of the register is executed. A microprogram control processing method characterized by: setting information on the next stage to be processed in the register at the end of execution of a stage, setting and activating a predetermined timeout value in the hardware timer, and returning to main processing. .