Instruction Register
From SnesLab
(Redirected from Instruction Reg)
The Instruction Register (IR) exists on the 65c816. It is 8 bits wide and contains the opcode just fetched from memory. It is not accessible to the programmer.
It is connected to the data latch/predecoder and instruction decode minterms.
References
- Labiak, page 39
- section 2.1 on page 6 of 65c816 datasheet, https://westerndesigncenter.com/wdc/documentation/w65c816s.pdf