Maxim Integrated DS4830A Optical Microcontroller - Manual (Page 225)

DS4830A User’s Guide
225
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 iteration, 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
0
C  Acc.15; Acc.[15:1] Acc.[14:0]; Acc.0  0
Encoding:
15 0
1000 1010 0010 1010
Example(s):
; Acc = E345h, C=0, S=1, Z=0
SLA ; Acc = C68Ah, C=1, S=1, Z=0
SLA ; Acc = 8D14h, C=1, S=1, Z=0
SLA2 Operation:
Carry Flag 15 Active Accumulator (Acc) 0
0
C
 Acc.14; Acc.[15:2] Acc.[13:0]; Acc.[1:0]  0
Encoding:
15 0
1000 1010 0011 1010
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
0
C  Acc.12; Acc.[15:4] Acc.[11:0]; Acc.[3:0]  0
Encoding:
15 0
1000 1010 0110 1010
Example(s):
; Acc = E345h, C=0, S=1, Z=0
SLA4 ; Acc = 3450h, C=0, S=0, Z=0