PM_Opc_SAR

== SAR = Shift Arithmetic Right ==

Hex	Mnemonic	Cycles
CE 88	SAR A	12
CE 89	SAR B	12
CE 8A nn	SAR [N+#nn]	20
CE 8B	SAR [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

; SAR Ds ; ; Ds = Source/Destination

Ds = (Ds AND 0x80) OR (Ds SHR 1)

Description

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

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

Conditions

Zero: Set when result is 0

Carry: Set when the old bit 0 was 1

Overflow: Always Reset (there's never a overflow)

Sign: Set when bit 7 of the result is 1

Examples

; A = 0x04 (4) SAR`` ``A ; A = 0x02 (2) ; F = (Zero=0):(Carry=0):(Overflow=0):(Sign=0)

; A = 0xFD (-4) SAR`` ``A ; A = 0xFE (-2) ; F = (Zero=0):(Carry=0):(Overflow=0):(Sign=1)

; B = 0x45 (69) SAR`` ``B ; B = 0x22 (34) ; F = (Zero=0):(Carry=1):(Overflow=0):(Sign=0)

; B = 0x84 (-124) SAR`` ``B ; B = 0xC2 (-62) ; F = (Zero=0):(Carry=0):(Overflow=0):(Sign=1)

; [HL] = 0x01 (1) SAR`` ``[HL] ; [HL] = 0x00 (0) ; F = (Zero=1):(Carry=1):(Overflow=0):(Sign=0)

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