Maxim Integrated DS4830 Optical Microcontroller - Manual (Page 214)

DS4830 User’s Guide
214
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