Load Accumulator With Shift
LACC
7-73
Assembly Language Instructions
Execution
Increment PC, then ...
Event
Addressing mode
(data-memory address)
×
2
shift
→
ACC
Direct or indirect
(data-memory address)
×
2
16
→
ACC
Direct or indirect (shift of 16)
lk
×
2
shift
→
ACC
Long immediate
Status Bits
Affected by
SXM
Description
The contents of the specified data-memory address or a 16-bit constant are
left shifted and loaded into the accumulator. During shifting, low-order bits are
zero filled. High-order bits are sign extended if SXM = 1 and zeroed if SXM = 0.
Words
Words
Addressing mode
1
Direct or indirect
2
Long immediate
Cycles for a Single LACC Instruction (Using Direct and Indirect Addressing)
Program
Operand
ROM
DARAM
SARAM
External
DARAM
1
1
1
1+p
SARAM
1
1
1, 2
†
1+p
External
1+d
1+d
1+d
2+d+p
† If the operand and the code are in the same SARAM block
Cycles for a Repeat (RPT) Execution of an LACC Instruction (Using Direct
and Indirect Addressing)
Program
Operand
ROM
DARAM
SARAM
External
DARAM
n
n
n
n+p
SARAM
n
n
n, n+1
†
n+p
External
n+nd
n+nd
n+nd
n+1+p+nd
† If the operand and the code are in the same SARAM block
Cycles for a Single LACC Instruction (Using Immediate Addressing)
ROM
DARAM
SARAM
External
2
2
2
2+2p
Cycles