What is timing and control in computer architecture?

Answer 1

Timing pulses are used in sequencing the micro-operations in an instruction. For example, when LDA instruction is executed, the memory is read operation is performed in timing pulse T1 and memory writer operation is performed in timing pulse T2. Now the combination of the signal LDA and T1 can be used as a control signal for performing read operation. Similarly, the combination of the signal LDA and T2 can be used as a control signal for performing write operation.

A master clock generator is used for controlling the timing for all register in a computer system. A state of a register cannot be changed by a clock pulse until it is enabled by the control signal, which are generated in the control unit and provide control inputs for multiplexers, processor register, and micro-operations. The control organization is of two types; hardwired control and micro-programmed control.

Hardwired ControlIn a hardwired control, the control signals are generated by using the collection of combinational circuits. The main advantage of the hardwired control is that, it can be optimized to produce a fast mode of operation. Whenever a change or modification is to be done in the design, then the wiring among the various components needs to be done. Micro-Programmed ControlIn a micro-programmed control, a control memory is used for storing control information which is also programmed for initiating the sequence of micro-operations. Whenever any change or modification is required in the design, it can be done by updating the micro-program in the control memory.