JPS607546A - Control system of general-purpose register - Google Patents

Abstract

PURPOSE:To attain high-speed operation with a simple constitution by providing a means which compares a save flag bit with a designated flag bit to detect the coincidence, and generating the program phenomenon record interruption processing when the coincident output of comparison is obtained. CONSTITUTION:A designated flag bit 4 is compared with a save flag bit 5 by a comparator 6 with correspondence of bit positions. Then a coincidence signal C is outputted when the coincidence of comparison is obtained at either bit position. Then an instruction is executed and the writing is carried out to a general- purpose register 2, for example. Thus the corresponding bit 5 is turned on. A program phenomenon record interruption is produced for rewriting of the register 2 before said instruction is executed. Therefore the signal C is outputted from the comparator 6 as long as the bit 4 is turned on by a program. This signal C is formed previously so as to cause an interruption factor.

Description

Detailed Description of the Invention (al) Technical Field of the Invention This invention relates to a program event recording interrupt method when a specified general-purpose register is rewritten in an interrupt processing method when an event specified by a program occurs.

(b) Background of the Technology One of the technologies related to the present invention is an instruction retry technology. This is a data processing device that has n general-purpose registers, and when an error occurs during the execution of an instruction, that instruction is interrupted and the instruction is executed again. The purpose of this is to prevent a decrease in the processing capacity of the entire data processing device due to interruption processing.

In order to retry this instruction, if the contents of the general-purpose register are rewritten before the error occurs, it is necessary to return the contents of the general-purpose register to the value before the instruction was executed before retrying the instruction.

For this reason, there is a method of storing the original value of the general-purpose register in a separate local memory, simultaneously with or before writing to the general-purpose register, during the execution process of the instruction. In this case, one entry in local storage is used to store the original value of one general-purpose register, and when stored, the save flag pin is turned on, indicating the validity of the entry.

One save flag VISO1- is provided for one entry in the local memory.

When attempting to transfer the instruction, control is performed so that the contents of the entry whose save flag bit is "1" are returned to the corresponding general-purpose register.

Another technique related to the present invention is program event recording interrupts. This is an interrupt that occurs when an event specified by a program occurs, such as an interrupt when a nibrun is successful.

Interrupt during instruction fetch.

Interrupt when writing to main storage.

Interrupt when rewriting general-purpose registers.

etc.

The present invention is related to the general-purpose register rewrite interrupt among these, and provides n specified flag pins in one-to-one correspondence for n general-purpose registers, and uses a program to select the n specified flag bits. The program event recording interrupt described in item 1iij is generated when an arbitrary bit is turned on and writing is performed to the specified σ register.

The present invention provides a save flag bit provided in a general-purpose register of a data processing device for the instruction retry, and a designated flag bit for generating the program event recording interrupt when writing to the general-purpose register is performed. This paper focuses on the function of , and attempts to consider a method for effectively performing program event recording interrupt processing for rewriting general-purpose registers.

(C) Conventional technology and problems Conventionally, when a program event recording interrupt occurs for rewriting a general-purpose register: - Every time an instruction finishes executing, a microprogram examines the register specification field of the executed instruction and determines the write line. Identifies the number of the general-purpose register specified.

■Or write the number of the general-purpose register written in.1. means is provided separately from the save flag focus for instruction retry.

That's what I was doing.

In method (2), since the general-purpose register numbers were identified in the microprogram, there were problems such as an increase in the number of steps in the microprogram and a long processing time for identification.

In the method (2), a flag bit with the same function as the save flag bit for instruction retry is separately provided, so there is a problem in that the amount of hardware increases.

(d) Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention provides a save flag for instruction retry, which a data processing device inherently has;
The purpose of this invention is to provide a method for speeding up program event recording interrupts for rewriting general-purpose registers by adding a small amount of hardware by using general-purpose register specification flag bits for program event recording interrupts. .

(e) Arrangement and object of the invention According to the invention, there is provided a plurality of general purpose registers and a local memory for retaining the original contents of said general purpose registers for instruction retry.

Further, in the data processing device, the data processing device has a save flag BISOTO indicating that the original data is retained in the local memory, and a designation flag PINTO specifying a program event recording interrupt condition for rewriting the general-purpose register. and a specified flag focus to detect a match, and provide a control method for causing a program event recording interrupt process when a match output is obtained from the match detecting means during execution of an instruction. This has the advantage that program event recording interrupt processing for general-purpose register rewriting can be sped up with the addition of a small amount of hardware.

(f) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

The figure is a block diagram showing an embodiment of the present invention, in which 1 is an arithmetic unit, 2 is n general-purpose registers (GR),
3 is a local memory (LS) provided in one-to-one correspondence with the n general-purpose registers (GR) 2, and is written to the general-purpose register (GR) 2 at the same time when an instruction is executed, or Before that, the general-purpose register (Gl?
) A register that stores the original value of 2 and is used when attempting to retry the instruction. 4ban general-purpose registers (GR
) Specified flag bit provided in a one-to-one correspondence with JJ) 2. Condition for generating a program event recording interrupt for rewriting a general-purpose register when writing is performed to a general-purpose register for which this flag bit is turned on. (In other words, simply having this specified flag bit turned on cannot be a cause of the program event recording interrupt for rewriting the general-purpose register). 5. This is also a save flag bit that is provided in one-to-one correspondence with n general-purpose registers (GR), and the general-purpose register (GR) 2 with this flag bit turned on has the information that is being executed at that time. This indicates that a write operation was performed by the command, and the present invention has been made with this point in mind. Reference numeral 6 denotes a comparison circuit necessary for carrying out the present invention, which is configured to compare designated flag bit 4 and save flag bit 5 in correspondence with bit positions, and if a match is found in any bit position, , outputs a coincidence signal (C).

Now, suppose that one instruction is executed and, for example, θ of #1 is written into the general register (GR) 2 of the #1, or before that writing.
) Original value of 2 is local storage (LS) Corresponding #1 of 3
The corresponding save flag bit (#1) 5 is set on.

Assuming that the specified flag bit (#1) 4 has been turned on by the program in order to generate a program event recording interrupt for rewriting a general-purpose register before this instruction is executed, the second write is executed. 71
At the time when the flag flag (#1) 5 is set on, the comparison circuit 6 outputs a coincidence signal (C).

Therefore, by configuring this match signal (C) to cause an interrupt, program event recording interrupt processing for general-purpose register rewriting can be performed.

Effects of the Invention As explained in detail above, according to the present invention, when a write operation is performed to a general-purpose register originally provided in a data processing device, the instruction retry function is turned on when a write operation is performed to a general-purpose register. Since it is configured to check for a match between the save flag bit and the specified flag bit that specifies the general-purpose register of the program event record interrupt for general-purpose register rewriting, a small amount of hardware is required to detect the match signal. By simply adding , it is possible to perform high-speed program event recording interrupt processing for rewriting general-purpose registers.

[Brief explanation of drawings]

The figure is a block diagram showing an embodiment of the present invention. In the drawing, 1 is an arithmetic unit, and 2 is a general-purpose register (GR).
, 3 is a local storage (LS), 4 is a designated flag bit, 5 is a save flag bit, and 6 is a comparison circuit.

Claims (1)

[Claims] It has a plurality of general-purpose registers, a local memory that retains the original contents of the general-purpose registers for instruction retry, and a save flag bit that does not indicate that the original data is retained in the local memory; In a data processing device having a specified flag bit that specifies a program event recording interrupt condition for rewriting a general-purpose register, means is provided to compare the save flag bit and the specified flag bit to detect a match, and when an instruction is executed, . A general-purpose register control method, characterized in that when a match output is obtained from the match detecting means, control is performed to cause a program event recording interrupt process.