Question

Give a control unit design for this processor usingD-flip-flopssimilar to the one we designedinthelectures for Vesp 1.0.The design should include fetch, decode and execute stepsin as much detail as possible.

Answer 1

Control unit design for this processor usingD-flip-flopssimilar to the one we designedinthelectures for Vesp 1.0.

Explanation:

1.We designed an ALU based on (a) building blocks such as multiplexers for selecting an operation to produce ALU output, (b) carry lookahead adders to reduce the complexity and (in practice) the critical pathlength of arithmetic operations, and (c) components such as coprocessors to perform costly operations such as floating point arithmetic. We also showed that computer arithmetic suffers from errors due to fintie precision, lack of associativity, and limitations of protocols such as the IEEE 754 floating point standard.

2.The datapath is the "brawn" of a processor, since it implements the fetch-decode-execute cycle. ... Simple datapath components include memory (stores the current instruction), PC or program counter (stores the address of current instruction), and ALU (executes current instruction).

3.A Hard-wired Control consists of two decoders, a sequence counter, and a number of logic gates. An instruction fetched from the memory unit is placed in the instruction register (IR). ... The operation codes from Bits 0 through 11 are applied to the control logic gates.

4.A control unit or CU is circuitry that directs operations within a computer's processor. It lets the computer's logic unit, memory, as well as both input and output devices know how to respond to instructions received from a program. Examples of devices that utilize control units include CPUs and GPUs.

5.There are two types of control units: Hardwired control unit and Microprogrammable control unit.

• Hardwired Control Unit

• Microprogrammable control unit

6.The control unit (CU) is a component of a computer's central processing unit (CPU) that directs operation of the processor. It tells the computer's memory, arithmetic/logic unit and input and output devices how to respond to a program's instructions