User’s Manual
C166S V1 SubSystem
Detailed Instruction Set
User’s Manual
6-8
V 1.6, 2001-08
ASHR
Arithmetic Shift Right
ASHR
Group
Shift and Rotate Instructions
Syntax
ASHR op1, op2
Source Operand(s)
op1
→
WORD
op2
→
shift counter
Destination Operand(s)
op1
→
WORD
Operation
(count)
←
(op2)
(V)
←
0
(C)
←
0
DO WHILE ((count)
≠
0)
(V)
←
(C)
∨
(V)
(C)
←
(op1[0])
(op1[n])
←
(op1[n+1]) [n=0...14]
(count)
←
(count) - 1
END WHILE
Description
Arithmetically shifts the destination word operand op1 right by the number of times as
specified by 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.
CPU Flags
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 in case of a shift count equal 0.
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.
E
Z
V
C
N
0
*
*
*
*
Содержание C166S V1 SubSystem
Страница 10: ...User s Manual C166S V1 SubSystem User s Manual I 6 V 1 6 2001 08...
Страница 16: ...User s Manual C166S V1 SubSystem Introduction User s Manual 1 6 V 1 6 2001 08...
Страница 126: ...User s Manual C166S V1 SubSystem Central Processing Unit User s Manual 3 96 V 1 6 2001 08...
Страница 178: ...User s Manual C166S V1 SubSystem Memory Organization User s Manual 4 52 V 1 6 2001 08...
Страница 206: ...User s Manual C166S V1 SubSystem Instruction Set User s Manual 5 28 V 1 6 2001 08...
Страница 306: ...User s Manual C166S V1 SubSystem Detailed Instruction Set User s Manual 6 100 V 1 6 2001 08...
Страница 362: ...User s Manual C166S V1 SubSystem The External Bus Interface User s Manual 8 40 V 1 6 2001 08...
Страница 452: ...User s Manual C166S V1 SubSystem General Purpose Timer Unit User s Manual 12 44 V 1 6 2001 08...
Страница 454: ...User s Manual C166S V1 SubSystem Instruction Index User s Manual 13 2 V 1 6 2001 08...
Страница 459: ......