Pokémon mini Development Documentation

SLA = Shift Arithmetic Left

Hex	Mnemonic	Cycles
CE 80	SLA A	3
CE 81	SLA B	3
CE 82 ll	SLA [BR:ll]	5
CE 83	SLA [HL]	4

Execute

A       = Register A
B       = Register B
[BR:ll] = Memory: (EP shl 16) or (BR shl 8) or #nn
[HL]    = Memory: (EP shl 16) or HL

; SLA Ds
;
; Ds = Source/Destination

Ds = Ds SLL 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)
• Negative: Set when bit 7 of the result is 1

Examples

; A = 0x04 (4)
SLA A
; A = 0x08 (8)
; SC = (Zero=0):(Carry=0):(Overflow=0):(Negative=0)

; A = 0xFE (-2)
SLA A
; A = 0xFC (-4)
; SC = (Zero=0):(Carry=1):(Overflow=0):(Negative=1)

; B = 0x45 (69)
SLA B
; B = 0x8A (-124)
; SC = (Zero=0):(Carry=0):(Overflow=1):(Negative=1)

; B = 0x84 (-124)
SLA B
; B = 0x14 (20)
; SC = (Zero=0):(Carry=1):(Overflow=1):(Negative=0)

; [HL] = 0x80 (-128)
SLA [HL]
; [HL] = 0x00 (0)
; SC = (Zero=1):(Carry=1):(Overflow=1):(Negative=0)

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