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PM_Opc_ROL

Jose I Romero edited this page Dec 6, 2019 · 1 revision

== 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)

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