Hyundai GMS800 Instruction Manual page 40

HYUNDAI MicroElectonics
DEC
( Decrement )

Function : M ( M )
Description : Decrement the contents of the accumulator or of the memory by 1.

Flag :
Mnemonic
DEC A
DEC dp
DEC dp + X
DEC !abs
DEC X
DEC Y
Example :
405
406
407
408 F868 1E03
409 F86A 3934
410 F86C AF
411 F86D 10FB
412 F86F 6F
DECW
: ( dp+1 ) ( dp ) = ( dp+1 ) ( dp ) − − − − 1
Function
Description : Decrement the contents of 16bit memory pair by 1.

Flag :
Mnemonic
DECW dp
Example :
529 C241 C40F
530 C243 3E3F
531 C245 BD05
532 C247 5D05
533 C249 7004
534 C24B C400
535 C24D 3E00
536 C24F DD03
36

1
OP Code
A8
A9
B9
B8
AF
BE
;**************************************
; ROTATE 32 BIT SHIFT LEFT
;**************************************
LDX
NextByte: ROL
DEC
BPL
RET
( Decrement word - 16bit )
OP Code
BD
LDA
LDY
DECW
CMPW
BNE
LDA
LDY
NEXT: TYA
Bytes Cycles
1 2
2 4
2 5
3 5
1 2
1 2
*
#3
34H+X ; SHIFT ROTATE LEFT
X ; DECREMENT INDEX COUNTER
NextByte
Bytes Cycles
2 6
#0FH
#03FH
CMPDATL
CMPDATL ; YA(030FH) - (CMPDATL+1)(CMPDATL)
NEXT
#0H
#0H
DPL