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Related to Microprogram: vertical microcode


(computer science)
A computer program that consists only of basic elemental commands which directly control the operation of each functional element in a microprocessor.



an associated set of microinstructions in digital computers. Each microinstruction indicates the machine micro-operations or micro-orders, the address of the next microinstruction, the duration of the microinstruction itself, and special actions relating to test operations. One microprogram can call out another as a microsubroutine. By changing the sequence and composition of the microinstructions—that is, by altering the structure of a microprogram—the system of instructions for a digital computer can be changed, thus adapting it to a certain class of problems or providing program compatibility with another digital computer.

Microprograms are usually stored in a specialized memory, which responds more rapidly than a direct-access memory. The length of a microprogram is usually 10–100 microinstructions, and a microinstruction requires 16–100 or more binary digits. The length of a microprogram in small digital computers is 256–1,024 16-digit words; in medium and large computers it is 1,024–8,196 words of 50 to 100 digits each.


Boulaye, G. Mikroprogrammirovanie. Edited by M. D. Pebart. Moscow, 1973. (Translated from French.)


References in periodicals archive ?
The resulting microprogram of Example VI is partially shown in Table 3.
Rotation (C) The cell receives the row output value No operation (N) The cell is not modified Shift (S) The cell receives the value from its prior one (left) Datum load (L) The cell is loaded with the value from the activation function or the input data Table 3: Part of the microprogram of Example VI.
RAMPM gives the first address of the MicroProgram on signal [[phi].
MicroProgram Memory (MPM) contains the MicroProgram with the word length r = int ([log.
A typical fragment represents a "sparse" microprogram.

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