0

MIPS ISA has 3 instruction formats: R, I, J. Each format being decode in the different way.
(R type - opcode | rs | rt | rd | shamt | funct) etc.
And we have some instruction - 10111010010000110011010101101110
How does CPU knows in which the way decode the instruction?

Vitaliy
  • 7
  • 2
  • 1
    In the simplest case the instruction is put into a special register (the IR) of the type PIPO (Parallel Input, Parallel Output) of length 32 bits. Then you have 32 outputs that you can use to drive the functional units. If you haven't attended a course on digital electronics (or read about it) it's a bit hard to visualise. I'd start from that, even a quick read should suffice. – Margaret Bloom Dec 04 '18 at 22:00
  • Some of the instruction bits signal the format, so the decode logic for the right format can be activated. – Peter Cordes Dec 05 '18 at 01:12

0 Answers0