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Statement Boundary Flagging

IP.com Disclosure Number: IPCOM000082818D
Original Publication Date: 1975-Feb-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 3 page(s) / 29K

Publishing Venue

IBM

Related People

Hajdu, J: AUTHOR [+4]

Abstract

The large volume of the microprograms used in electronic data processing systems, which offer the user a plurality of functions, necessitates that the means employed for preparing the programs increase the program efficiency and permit error-free programs to be readily generated, and errors, if any, to be equally readily diagnosed.

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Statement Boundary Flagging

The large volume of the microprograms used in electronic data processing systems, which offer the user a plurality of functions, necessitates that the means employed for preparing the programs increase the program efficiency and permit error-free programs to be readily generated, and errors, if any, to be equally readily diagnosed.

To this end, high-level programming languages generating the actual microcode by compilers are used to advantage. The generated microcode is subsequently executed in the machine.

For the programmer who uses high-level programming languages the compiler-generated code is very difficult to interpret, and thus remains "hidden" from him.

In the machine only the compiler-generated code is executed. This discrepancy renders the search operation of the machine microprogram very difficult.

During compilation, a number of microinstructions are generated for each high-level language statement. These instructions can generally not be interpreted by the programmer. Therefore, it is necessary that the microprogram be run in the machine during particular time intervals, each of which corresponds to one high-level language statement. This enables the programmer to check whether the instructions of the individual statements are being executed.

While executing the microprogram, the machine can determine the boundaries of the high-level language statements.

One way of solving this problem would be to reserve an additional bit for each microinstruction. This bit would be compiler-generated for the respectively first microinstructions of the statements, and be entered into an additional bit position of the first instruction of a sequence representing the statements.

During the execution of the microprogram an auxiliary logic determ...