ST10 FAMILY PROGRAMMING MANUAL
45/172
ASHR
Arithmetic Shift Right
Syntax
ASHR op1,
op2
Operation
(count) <--
(op2)
(V) <--
0
(C) <--
0
DO WHILE (count)
≠
0
(V)
<-- (C) v (V)
(C) <--
(op1
0
)
(op1
n
) <--
(op1
n+1
) [n=0...14]
(count)
<-- (count) - 1
END WHILE
Data Types
WORD
Description
Arithmetically shifts the destination word operand op1 right by as many times as specified in the source
operand op2. To preserve the sign of the original operand op1, the most significant bits of the result are
filled with zeros if the original most significant bit was a 0 or with ones if the original most significant bit
was a 1. The Overflow flag is used as a Rounding flag. The least significant bit is shifted into the Carry.
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.
Flags
Addressing Modes
E
Z
V
C
N
0
*
S
S
*
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 least significant bit 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
Format
Bytes
ASHR
Rw
n
, Rw
m
AC nm
2
ASHR
Rw
n
, #data
4
BC #n
2
Содержание ST10 Series
Страница 2: ......
Страница 4: ...ST10 FAMILY PROGRAMMING MANUAL 2 172...