Microprogrammed Control
Microprogrammed Control
English | 2021 | ISBN: B097ZGM2TZ | 38 pages | PDF,EPUB,AZW3 | 4.72 MB
English | 2021 | ISBN: B097ZGM2TZ | 38 pages | PDF,EPUB,AZW3 | 4.72 MB
Microprogrammed Control
The control signals needed in each step of intruction execution can be generated by the finite state machine method, also called hardwired control, or, alternatively, by the microprogrammed control method discussed below.
Basic Concepts of Microprogramming:
Control word (CW):
A word with each bit for one of the control signals. Each step of the instruction execution is represented by a control word with all of the bits corresponding to the control signals needed for the step set to one.
Microinstruction:
Each step in a sequence of steps in the execution of a certain machine instruction is considered as a microinstruction, and it is represented by a control word. All of the bits corresponding to the control signals that need to be asserted in this step are set to 1, and all others are set to 0 (horizontal organization).
Microprogram:
Composed of a sequence of microinstructions corresponding to the sequence of steps in the execution of a given machine instruction.
Microprogramming:
The method of generating the control signals by properly setting the individual bits in a control word of a step.