PM Opc SAL

SAL = Shift Arithmetic Left

Hex	Mnemonic	Cycles
CE 80	SAL A	12
CE 81	SAL B	12
CE 82	SAL [N+#nn]	20
CE 83	SAL [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

; SAL Ds
;
; Ds = Source/Destination

Ds = Ds SHL 1

Description

"8-Bits Destination" bits are arithmetically shifted left by 1.

NOTE: This instruction can be used as an signed integer multiplication by 2.

Conditions

Zero: Set when result is 0

Carry: Set when the old bit 7 was 1

Overflow: Set when result overflow 8-bits signed range (< -128 OR > 127)

Sign: Set when bit 7 of the result is 1

Examples

; A = 0x04 (4)
SAL A
; A = 0x08 (8)
; F = (Zero=0):(Carry=0):(Overflow=0):(Sign=0)

; A = 0xFE (-2)
SAL A
; A = 0xFC (-4)
; F = (Zero=0):(Carry=1):(Overflow=0):(Sign=1)

; B = 0x45 (69)
SAL B
; B = 0x8A (-124)
; F = (Zero=0):(Carry=0):(Overflow=1):(Sign=1)

; B = 0x84 (-124)
SAL B
; B = 0x14 (20)
; F = (Zero=0):(Carry=1):(Overflow=1):(Sign=0)

; [HL] = 0x80 (-128)
SAL [HL]
; [HL] = 0x00 (0)
; F = (Zero=1):(Carry=1):(Overflow=1):(Sign=0)

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