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SHR
Syntax
Operation
Data Types
Description
Condition Flags
Addressing Modes
Semiconductor Group
30Mar98@15:00h
Shift Right
SHR
op1, op2
(count) ← (op2)
(C) ← 0
(V) ← 0
DO WHILE (count) ≠ 0
(V) ← (C) ∨ (V)
(C) ← (op1
)
0
) ← (op1
(op1
) [n=0...14]
n
n+1
) ← 0
(op1
15
(count) ← (count) - 1
END WHILE
WORD
Shifts the destination word operand op1 right by as many times as speci-
fied by the source operand op2. The most significant bits of the result are
filled with zeros accordingly. Since the bits shifted out effectively represent
the remainder, the Overflow flag is used instead as a Rounding flag. This
flag together with the Carry flag helps the user to determine whether the
remainder bits lost were greater than, less than or equal to one half an
LSB. Only shift values between 0 and 15 are allowed. When using a GPR
as the count control, only the least significant 4 bits are used.
E
Z
0
*
E Always cleared.
Z Set if result equals zero. Cleared otherwise.
V Set if in any cycle of the shift operation a '1' is shifted out of the carry
flag. Cleared for a shift count of zero.
C The carry flag is set according to the last LSB shifted out of op1.
Cleared for a shift count of zero.
N Set if the most significant bit of the result is set. Cleared otherwise.
Mnemonic
SHR
Rw
, Rw
n
SHR
Rw
, #data4
n
C166 Family Instruction Set
V
C
N
S
S
*
Format
6C nm
m
7C #n
106
Instruction Description
Version 1.2, 12.97
SHR
Bytes
2
2
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