ROL = Rotate Left
| Hex | Mnemonic | Cycles |
|---|---|---|
| CE 94 | ROL A | 12 |
| CE 95 | ROL B | 12 |
| CE 96 nn | ROL [N+#nn] | 20 |
| CE 97 | ROL [HL] | 16 |
Execute
A = Register A
B = Register B
[N+#nn] = Memory: (I shl 16) or (N shl 8) or #nn
[HL] = Memory: (I shl 16) or HL
; ROL Ds
;
; Ds = Source/Destination
Ds = (Ds SHL 1) OR (Ds SHR 7)
Description
"8-Bits Destination" bits are rotated left by 1.
Conditions
Zero: Set when result is 0
Carry: Set when bit 0 of the result is 1
Sign: Set when bit 7 of the result is 1
Overflow remain unchanged
Examples
; A = 0x04
ROL A
; A = 0x08
; F = (Zero=0):(Carry=0):(Sign=0)
; B = 0x45
ROL B
; B = 0x8A
; F = (Zero=0):(Carry=0):(Sign=1)
; B = 0x84
ROL B
; B = 0x15
; F = (Zero=0):(Carry=1):(Sign=0)
; [HL] = 0x80
ROL [HL]
; [HL] = 0x01
; F = (Zero=0):(Carry=1):(Sign=0)