Specifications

ROtaA Right
ROR dst
2.3~
dst
01 lOI I I 6 I .I 0 , I I I I 1
15
6 5 0
Condition Codes: Z: set if all bits of result = 0; cleared otherwise.
N: set if the high-order bit of the result is set; cleared
otherwise
C: loaded with the low-order bit of the destination
V: loaded with the Exclusive OR of the N-bit and C-bit
(as set by the completion of the rotate operation).
Description: Rotates all bits of the destination right one place. Bit 0 is loaded
into the C-bit of the status word and the previous contents of the’C-bit are
loaded into bit 15 of the destination. ’
ROtato Left
ROL dst
2.3~
0 1 0
I 16, I I I I 1 I I 1 I 1
1
dst
15
6 5
0
Condition Codes: Z: set if all bits of the result word = 0; cleared other-
wise
N: set if the highlorder bit of the result word is set;
cleared otherwise
C: loaded with the high-order bit of the destination
V: loaded with the Exclusive OR of the N-bit and C-bit
(as set by the completion of the rotate operation)
Description: Rotates all bits of the destination left one place. Bit 15 is loaded
into the C-bit of the status word and the previous contents of the C-bit are
loaded into bit 0 of the destination.
SWAO Bytes SWAB dst
2.3~
01 10, I 10, .I 131
dst
I I
I I
15
6 5 0
Condition Codes: Z: set if low-order byte of result = 0; cleared otherwise
N: set if high-order bit of low-order byte (bit 7) of result
is set: cleared otherwise
C: cleared
V: cleared
Description: Exchanges high-order byte and low-order byte of the destination
word (dst must be a word address).
Shifts-Scaling data by factors of 2 is accomplished by the shift instructions:
ASR-Arithmetic Shift Right
ASL-Arithmetic Shift Left
The sign bit (bit 15) of the operand is replicated in shifts to the right. The
low-order bit is filled with 0 in shifts to the left. Bits shifted out of the C-bit
are lost.
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