1989_MELPS_7700_Software_Manual

LSR Logical Shift Right LSR
Operation
When m=O
When m=1
b7
bo
Description
Shifts all bits of the accumulator or memory one place to the right. Bit 15 (or bit
7 if the data length selection flag m is set to 1) of the accumulator or memory is
loaded with O.
The carry flag C is loaded from bit 0 of the data before the shift.
Status flags
IPL : Not affected.
N Cleared to "0".
V Not affected.
m Not affected.
x
o
I
Not affected.
Not affected.
Not affected.
Z Set to 1 when the result of operation is O. Otherwise, cleared to O.
C Set to 1 when bit 0 before the operation is 1. Otherwise, cleared to O.
Addressing mode Syntax Machine code I Bytes Cycles
Accumulator LSR A 4A16
Direct LSR dd 4616, dd 7
I:
Direct indexed X LSR dd, X 5616, dd
7
Absolute LSR mmll 4E16, II, mm 7
Absolute indexed X LSR mmll, X 5E16, II, mm 8
(Note1) The accumulator addressing mode's specification In thiS table applies when uSing the accumulator
A. If using the accumulator B, replace "A" with "B". In this case, "4216" is added at the beginning
of the machine code, the bytes-count increases by 1 and the cycles-count increases by 2.
I~
2
99