Q. Explain about Instruction Register and Flags?
The Instruction Register: It comprises the operation code (opcode) and addressing mode bits of the instruction. It assists in determining the numerous cycles to be performed and hence determines related micro-operations that are required to be performed.
Flags: Flags are used by CU for determining the status of CPU and the results of a previous ALU operation. For illustration a zero flag if set conveys to control unit that for instruction ISZ (skip subsequent instruction if zero flag is set) the next instruction has to be skipped.