JPS5929891B2 - Data transfer method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data transfer method between a plurality of data processing devices connected via a bus, and in particular, to a method for transferring data from a central processing unit to a main memory or an input/output device. Concerning data transfer methods.

Conventionally, there have been the following data transfer methods of this type.

To explain with reference to FIG. 1, when transferring data from the central processing unit 1 to the main memory or the input/output device 2, the central processing unit 1 first transfers the data to the output register 4 via the internal bus 3. and then sends the control signal TC to the input/output device 2. In response, the input/output device 2 reads the contents of the output register 4, checks the contents for errors, and sends the resulting check signal CHK to the central processing unit 1. If the check signal indicates that an error has occurred, the processing after sending the control signal TC described above is repeated, that is, retried.

However, if a data error occurs in the output register 4, correct data cannot be transferred to the input/output device 2 even if such a retry is performed.

Conventional data transfer methods cannot eliminate data errors that occur in the output register as described above, and in order to eliminate such data errors, the data must be recalculated on the output register and the results must be retransmitted. This process has the drawback of degrading the performance of the central processing unit.

This invention was made in order to eliminate the drawbacks of the conventional method as described above, and when data is transferred from the central processing unit to the output register, this data is also transferred to another register and stored. The present invention aims to provide a data transfer method that improves the performance of a central processing unit and the reliability of data transfer by transferring the contents of a register to an output register during a retry.

An embodiment of the present invention will be described below with reference to the block diagram shown in FIG. Reference numerals 1 to 4 in FIG. 2 are the same as those explained in FIG. 1. The central processing unit 1 transfers data to be transferred to the input/output device 2 to the output register 4 via the internal bus 3, and also transfers this data to the register 5.
It is also transferred and stored. The data stored in the register 4 is transferred to the input/output device 2 in the same manner as described above.
From this, a check signal CHK is sent to the central processing unit 1. When the check signal CHK indicates the presence of an error, the central processing unit 1 transfers the data in the register 5 to the output register 4 via the internal bus 3 and outputs the control signal T.
Execute the retry following the sending of C.

Note that the register 5 may be connected to the output bus 3.

In this case, data errors occurring on the output bus 3 cannot be repaired, but data errors occurring in the output register 4 and beyond can be repaired. As described above, according to the present invention, data errors occurring after the output register can be easily corrected, the reliability of data transfer can be improved, and the performance of the data processing device can be improved.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the conventional data transfer method;
The figure is a block diagram showing a data transfer system according to an embodiment of the present invention. 1...Central processing unit, 2...Main memory or input/output device, 4...Output register, 5...
·····register.

Claims (1)

[Claims] 1 In a data transfer method in which calculation result data calculated by a first data processing device is transferred to a second data processing device via an output register and a bus, the register that stores the data is transferred to the first data processing device. connect to
When a data error occurs in the data transferred to the second data processing device via the output register, the content of the output register is updated according to the content of the register, and the data transfer is repeated. Data transfer method.