CSC258H1 Lecture Notes - Register File, Instruction Register, Control Unit
Document Summary
Control unit takes in the opcode from the current instruction, and sends signals to the rest of the processor. Within the control unit is a finite state machine that can occupy multiple clock cycles for a single instruction. The control unit send out different signals on each clock cycle, to make the overall operation happen. The control unit sends signals (orange lines) to various processor componenets to enact all possible operations: control unit signals. Write the alu output to the pc. Write the alu output to the pc only if the zero condition has been met. For branching, alu comparison, usually test conditions for registers; if condition meet zero high. Ex. reg1 > reg2, or reg3 == 0. For memory access; short for instruction or data . Signal whether the memory address is being provided by the pc (for instruction) or an alu operation (for data) Can be x if not writing to memory.