Computer architecture

To see how different ISA decisions will impact the machine design, consider designing an accumulator machine with the following specifications:

224 words of memory [words are 32-bit wide]

Fixed format instructions

A 32-bit accumulator register (AC)

An index register X

Index address mode: address field + X when indexing is indicated in the instruction

Capable of performing a total of 128 operations

a) Write the equivalent machine level language corresponding to a C statement of C = A + B

b) Give an instruction format for this computer. To do this draw a diagram of the instruction format with each field clearly specified. For each field indicate its size, the reason for selected size, and a description of what purpose the field.