JPS604492B2 - calculator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a computer capable of mutual communication between a microprogram and a machine language program.

In conventional computers, programs are expressed as a series of machine language instructions, and the computer extracts and executes the machine language instructions one by one without being aware of the relationships between the machine language instructions.

Therefore, for example, when another sequence calls and executes a sequence from one position to another in the program, it is necessary to embed a branch instruction in advance at the end of the former sequence. Also, some parts of the program
Even in the case of control in which a sequence is repeatedly executed until a condition is met, it is necessary to embed a control command at an appropriate position in the program. Such a method not only requires preprocessing for embedding instructions, but also
The drawback is that the number of instructions increases and the execution time takes longer. SUMMARY OF THE INVENTION An object of the present invention is to provide a computer capable of exchanging control between a microprogram and machine language in order to eliminate these drawbacks.

Another object of the present invention is to provide a computer capable of starting execution of a designated part of a program from a microprogram.

Another object of the present invention is to provide a computer capable of returning control to the microprogram that started the program when execution of a specified position in the program started from the microprogram is completed.

That is, the computer of the present invention includes a first storage means for storing a first position on the program, a second storage means for storing a second position on the program, and a second storage means for storing the first position on the program. means for executing a microinstruction for initiating a program sequence from a location to a second location on said program and saving a return microinstruction location after execution of said program sequence is completed; a third storage means for storing; a detection means for checking from time to time whether the instruction position of the program sequence being executed matches the contents of the second storage means; and when the detection means detects a match. and means for returning control to a microinstruction position indicated by the third storage means, to control execution of a designated sequence on the program from the microprogram.

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

[SOURCE] in Figure 1 is D in the FORTRAN language.
This is an example of the O instruction, and shows a program that returns statements 0101 to 1000 five times. [OBJECT] (machine language instruction sequence) in Figure 1 is
This is an example of a machine language object of the above DO routine in a conventional computer. where instruction step 00100,
01000 and 01001 are control instructions inserted to implement statement 0100 of [SOURCE], which are usually generated by the compiler, and are realized by the microprogram reading each instruction step and repeating execution. . FIG. 2 is an example of a machine language object used in the present invention that corresponds to [SOURCE] in FIG.
This indicates that the instruction is executed repeatedly up to 00 five times.

FIG. 3 shows an example of a microprogram that implements the machine language shown in FIG. 2, and FIG. 4 is a block diagram showing an embodiment of the present invention.

In order to simplify the explanation, FIG. 4 shows only the parts necessary for explaining the present invention, and does not particularly describe the parts performed in a conventional microprogram controlled computer. That is, the microprogram control device 401 in FIG. 4 is a normal microprogram control device equipped with a microprogram input register, a microprogram decoding circuit, an arithmetic circuit for address calculation, a shift circuit, a mask circuit, an internal register, etc. The microprogram sequence counter 410 also reads the microinstruction by giving the address of the control storage device 411.
Various control signals are generated depending on the content. The detailed configuration and operation of the above control device 401 can be found in the publication "Information Processing" (Vol.
．． 14, No. 6), pages 379 to 387 (particularly FIG. 2). Also, START402 and E
ND403 is a register that stores the start and end addresses of machine language routines to be started from the microprogram, and in the DO instruction executed in the present invention,
START402 stores the machine language address immediately after the DO instruction (0101 in Figure 2), and END403 stores the CON
The machine language address (1000 in FIG. 2) of the TINUE statement is stored. The PSC 404 is a program sequence counter, and the machine language is retrieved from the address in the main memory 406 indicated by the contents. The microprogram that executes the DO instruction sets the start address of the machine language sequence to be started (stored in START402) in the PSC4.
04 to activate that sequence. The comparison circuit 405 compares the main memory address of the machine language sequence started from the microprogram (the contents of the PSC 404 and is updated every machine language step) and the END4
This circuit compares the contents of 03 from time to time and sets a flip-flop (hereinafter referred to as FF) 407 when they match. RTN 408 is a register that stores the return microinstruction address after the final machine language instruction of the machine language sequence started by the microprogram is executed. When the control device 401 detects that the FF 407 is set, the control device 401 changes the contents of the register RTN 408 to the MSC.
410 returns control to the microprogram for the DO instruction. Next, the flow of the microroutine shown in FIG. 3 will be explained in more detail in correspondence with FIG. 4.

Microprogram control begins with execution of the machine language instruction fetch phase in main memory 406 starting at MOOO in FIG.

That is, in FIG.
1' generates microprogram address MOO0,
Bus bar 430, multiplexer (hereinafter referred to as MPX) 40
9 and bus 431 to MSC4 1 0' MO
When OO is set, one microinstruction is retrieved from control store 411, which is decoded by microprogram controller 401 to generate various control signals before the next microinstruction is retrieved. A decoding circuit (not shown) in the device 401 decodes the bit pattern of the operation code (instruction instruction code) of the machine language instruction read by repeating the execution of this microinstruction, and as a result, it is determined that the instruction is a DO instruction. Once this is known, microprogram control enters the DO instruction execution phase starting from MOIO in FIG. The machine language DO instruction is shown in step 0100 in Figure 2, and has the final address (1000) of the routine to be repeatedly executed and the number of repetitions (5) as parameters, and these two are The parameter and the address (0101) immediately after the DO command, which is the starting address of the repeat routine, are the controller 4.
01 internal register (not shown).
In steps MOI0, MOI1, and MO12 in FIG. 3, after saving the number of repetitions, the start address of the repeat routine is set in the START 402 register via the bus 420, and the end address is set in the END 403 register via the bus 422. In step MO13, the signal line 434
START40
Set the start address of the machine language routine stored in 2 to bus 4.
Program sequence counter PSC4 via 21
04, and sets the machine language instruction fetch start address MOOO of the microprogram to MSC4101.
Thereafter, the control device 401 uses the microroutine in the control storage device 411 to repeatedly retrieve the machine language from the storage location of the main storage device 406 pointed to by the PSC 404, execute it, and update the PSC 404. During the execution of the machine language routine started by the above operation, the PSC4
The contents of 04 and END403 are sent to the comparison circuit 405 via buses 424 and 423, respectively, and compared, and when they match, the comparison circuit 405 sends the contents of FF4 via the signal line
Set 07. At the MOOO step in FIG. 3, which is the beginning of the microprogram machine language extraction routine, the microprogram control device 401 tests via the signal line 427 whether or not the FF 407 is set.
As a result of the test, if it is detected that it is set,
The control device 401 transfers the contents of the RTN 408 to the bus line 429.
, MPX409, and MSC41 via bus 431
MPX40 by releasing a signal to the signal line 433 to send it to 0.
Switch 9. This operation causes the microprogram control to proceed to the execution of step MO14 in FIG. MO1
In step 4, reset the FF 407, subtract the number of repetitions COUNT, and if you want to execute the machine language again, branch to step MO13, otherwise proceed to the next M
Proceeding to O15, final processing of the DO command is performed. Although a simple example has been described above to explain the computer of the present invention, this is merely an example and does not limit the scope of the present invention.

That is, in the above description, the DO command in the FORTRAN language was used as an example, but the present invention can also be applied to other languages as long as the command starts a machine language sequence. For example, PERFORM A THRU B N TIMES, which is one of the PERFORM instructions in the COBOL language.
．． The command sets the start address of processing procedure A and the end address of processing procedure B to START402 and END4 in FIG. 4, respectively.
It can be executed in exactly the same way by creating a microprogram that stores it in 03 and executes it by returning N lines.

In the above explanation, it is not allowed to include a DO instruction (NEST) in the program sequence executed by the DO instruction, but registers START402 and END4 in FIG.
03, Add pushdown and popup control by using a LIFO type register file (stack) instead of the RTN408 and internal registers (not shown) (used in MOI0 and MO14 of the microroutine in Figure 3). For example, the NEST processing described above can be executed.

At this time, it goes without saying that the matching flip-flop FF 407 must be set and reset under appropriate control. In the above explanation, we have described a method for testing whether the final instruction of a program sequence has been executed using microinstructions (MOOO step in Figure 3), but this part is a combinational circuit (hardware).
It is also possible to realize this by

In the above explanation, a register is used as a means of storing addresses,
Although a comparison circuit is used as a means for detecting execution of the final address of a program sequence, a part or all of this may be realized by a microprogram.

In addition, in the above example, the DO command of the FORTRAN language was used as an example to describe control that repeats a machine language sequence a specified number of times, but it can also be applied to control that repeats a machine language sequence until a specified condition is met. .

For example, PERFORM AT of COBOL language
HRU B UNTIL CONDITION. This instruction instructs to check the condition indicated by CONDITION every time the sequence from A to B is executed and execute it repeatedly until the condition is satisfied.In order to realize this with the computer of the present invention, , MO in Fig. 3
After the 14th step, it is sufficient to add control to check the conditions and perform conditional branching based on the results.

Here, the control for checking the condition may be written in a microprogram, but it is also possible to call a condition test routine written in a machine language program by performing an operation corresponding to the DO command again.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a source program including a FORTRAN language DO instruction and a corresponding machine language object in a conventional computer, and FIG. 2 is a diagram showing an example of a computer using the computer of the present invention corresponding to the source program in FIG. 3 is a diagram showing an example of a word object, FIG. 3 is a diagram showing a microroutine for executing the machine language DO instruction of FIG. 2, and FIG. 4 is a block diagram showing an embodiment of the present invention. In FIG. 4, 401 is a microprogram control device, 402 is a register (START), 403 is a register (END), 404 is a power counter PSC, 405 is a comparison circuit, 406 is a main memory, 407 is a flip-flop,
408 is a register (RTN), 409 is a multiplexer, 410 is a power counter (MSC), and 411 is a control storage device. Figure O Figure O 2 Figure O 3 Figure O 4

Claims (1)

[Claims] 1 a first storage means for storing a first position on the program; a second storage means for storing a second position on the program; and a first storage means for storing a second position on the program; means for executing a microinstruction for activating a program sequence up to position 2 and storing a return microinstruction position after execution of said program sequence is completed; and third storage means for storing said return microinstruction position. a detection means for checking from time to time whether the instruction position of the program sequence being executed matches the contents of the second storage means; and when the detection means detects a match, the third storage means 1. A computer comprising: means for returning control to a designated microinstruction position, and controlling execution of a designated sequence on said program from a microprogram.