NEC PD750008 Manuale Utente
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CHAPTER 11 INSTRUCTION SET
11.4.5 Accumulator Manipulation Instructions
RORC A
Function: CY <- A
0
, A
n-1
<- A
n
, A
3
<- CY (n = 1–3)
Rotates the contents of the A register (4-bit accumulator) through the carry flag one bit position to the right.
NOT A
Function: A <– A
Obtains the one’s complement of the A register (4-bit accumulator), that is, inverts each bit of the A register.
11.4.6 Increment/Decrement Instructions
INCS reg
Function: reg <– reg+1 ; Skip if reg = 0
Increments the contents of register reg (X, A, H, L, D, E, B, C). If the result of increment produces reg =
0, the immediately following instruction is skipped.
INCS rp1
Function: rp1 <– rp1+1 ; Skip if rp1 = 00H
Increments the contents of register pair rp1 (HL, DE, BC). If the result of increment produces rp1 = 00H,
the immediately following instruction is skipped.
INCS @HL
Function: (HL) <– (HL)+1 ; Skip if (HL) = 0
Increments the data at the data memory location addressed by the HL register pair. If the result of increment
produces data that is 0, the immediately following instruction is skipped.
0
CY
0
3
1
2
0
1
1
0
Before
execution
execution
1
0
0
1
0
After
execution
execution
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RORC A
A