What is the general format of TurboGrafX processor instructions?
For example, and this is made up: one word for opcode + two words for flags + one word for every parameter listed under that instruction.
Please be specific.
Retrocomputing Stack Exchange is a question and answer site for vintage-computer hobbyists interested in restoring, preserving, and using the classic computer and gaming systems of yesteryear. It only takes a minute to sign up.Sign up to join this community
The HuC6280 used an instruction set and architecture which was largely identical to the 65C02 -- each instruction is represented by a one-byte opcode, followed by up to three bytes of immediate data. The amount of immediate data is implied by the opcode.
(The flags are a CPU register, not part of an instruction.)
The HuC6280 appears to support all instructions which existed on the 65C02, plus some additional instructions. Some of these instructions are specific to the PC-Engine hardware, while others are more general-purpose:
BSR: A form of
JSR which uses a relative address.
CLY: One-byte instructions to set specific registers to zero.
CSL: Instructions to change the speed of the processor.
SXY: Swap values between the
SET: Acts as a prefix, causing the next instruction to use
(X) -- that is, a zero-page memory value -- instead of
ST2: Store immediate values to VDC control registers.
TMA: Store and retrieve values to/from memory mapper registers.
TII: Control memory-move operations.