Hi,
Here's a way to implement single cycle resolution without the use of the
carry flag (which adds overhead in the setup and at the end):
; A is assumed to hold the delay value plus the offset address of JumpTable.
; Or, you can align JumpTable to a page boundary.
sta indjmp
jmp (indjmp) ; point indjmp+1 to JumpTable somewhere in your init code
JumpTable:
dc.b $C9
dc.b $C9
; repeat as many $C9's as you need for the maximum number of cycles you
; you need to delay by.
dc.b $C9 ; opcode: CMP immediate (4 cycles: uses the $C5, executes
; the NOP below.)
dc.b $C5 ; opcode: CMP zero page (3 cycles, uses up the NOP as a
; destination address of $EA)
nop ; opcode: NOP (2 cycles by itself)
You may find the reduced overhead of this technique useful.
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