SLA/SLA2/SLA4 Shift Accumulator Left Arithmetically
One, Two, or Four Times
Description: Shifts the active accumulator left once, twice, or four times respectively for SLA, SLA2, and SLA4. For each shift iter-
ation, a 0 is shifted into the lsb, and the msb is shifted into the Carry (C) flag. For signed data, this shifting process
effectively retains the sign orientation of the data to the point at which overflow/underflow would occur.
Status Flags: C, S, Z
SLA Operation: Carry Flag 15 Active Accumulator (Acc) 0
C ← Acc.15; Acc.[15:1]← Acc.[14:0]; Acc.0 ← 0
Encoding: 15 0
Example(s): ; Acc = E345h, C=0, S=1, Z=0
SLA ; Acc = C68h, C=1, S=1, Z=0
SLA ; Acc = 8D14h, C=1, S=1, Z=0
SLA2 Operation: Carry Flag 15 Active Accumulator (Acc) 0
C ← Acc.14 ; Acc.[15:2]← Acc.[13:0] ; Acc.[1:0] ← 0
Encoding: 15 0
Example(s): ; Acc = E345h, C=0, S=1, Z=0
SLA2 ; Acc = 8D14h, C=1, S=1, Z=0
SLA4 Operation: Carry Flag 15 Active Accumulator (Acc) 0
C ← Acc.12; Acc.[15:4]← Acc.[11:0]; Acc.[3:0] ← 0
Encoding: 15 0
Example(s): ; Acc = E345h, C=0, S=1, Z=0
SLA4 ; Acc = 3450h, C=0, S=0, Z=0
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