Compare Instructions - NEC PD750004 User Manual

4 bit single-chip microcomputer
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µPD750008 USER'S MANUAL
INCS mem
Function: (mem) <– (mem)+1 ; Skip if (mem) = 0, mem = D
Increments the data at the data memory location addressed by the 8-bit immediate data mem. If the result
of increment produces data that is 0, the immediately following instruction is skipped.
DECS reg
Function: reg <– reg–1 ; Skip if reg = FH
Decrements the contents of register reg (X, A, H, L, D, E, B, C). If the result of decrement produces reg
= FH, the immediately following instruction is skipped.
DECS rp'
Function: rp' <– rp'–1 ; Skip if rp' = FFH
Decrements the contents of register pair rp' (XA, HL, DE, BC, XA', HL', DE', BC'). If the result of decrement
produces rp' = FFH, the immediately following instruction is skipped.

11.4.7 Compare Instructions

SKE reg,#n4
Function: Skip if reg = n4
Skips the immediately following instruction if the contents of register reg (X, A, H, L, D, E, B, C) match the
4-bit immediate data n4.
SKE @HL,#n4
Function: Skip if (HL) = n4
Skips the immediately following instruction if the data at the data memory location addressed by the HL
register pair match the 4-bit immediate data n4.
SKE A,@HL
Function: Skip if A = (HL)
Skips the immediately following instruction if the contents of the A register match the data at the data memory
location addressed by the HL register pair.
280
n4 = I
: 0-FH
3-0
n4 = I
: 0-FH
3-0
: 00H-FFH
7-0

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