Status: Tags: Links: Instruction Set Architecture (ISA)
Creating an ISA (x295M)
Principles
Example is x295M
Registers and memory model
?
- Number of registers
- 0
- Each memory adress bit count
- m = 32
- Word size = 32 bits
- Byte-adressable memory ?
- Implies n = 1 byte
- Memory size = 2^m x n
Set of instructions
Add, Sub, Mul
General format
{Opcode (2)} {dest (30)} {00} {src1(30)} {00} {src2(30)}
- Each pair of 2 bits + var is 32 bits = 1 word
Follows design guideline since:
- Few as possible created
- 1 format
- Formats are same length
- 3 x 32 bits
- Same purpose in same location
- Only 1 format so yes
Assembly to Machine
- Keep in mind how the operands are stored as assembly might be different from machine
References:
Created:: 2022-03-21 20:13