This table indicates the number of clock periods for the shift and rotate instructions. The number of read and write cycles is shown in parenthesis as (r/w). The number of clock periods and the number of read and write cycles must be added respectively to those of the effective address calculation where indicated.
Shift/Rotate Instruction Execution Times
Instruction | Size | Register | Memory |
ASR,ASL | byte,word | 6 + 2n ( 1 / 0 ) | 8 ( 1 / 1 ) + |
long | 8 + 2n ( 1 / 0 ) | – | |
LSR,LSL | byte,word | 6 + 2n ( 1 / 0) | 8 ( 1 / 1 ) + |
long | 8 + 2n ( 1 / 0 ) | – | |
ROR,ROL | byte,word | 6 + 2n ( 1 / 0 ) | 8 ( 1 / 1 ) + |
long | 8 + 2n ( 1 / 0 ) | – | |
ROXR,ROXL | byte,word | 6 + 2n ( 1 / 0 ) | 8 ( 1 / 1 ) + |
long | 8 + 2n ( 1 / 0) | – |
+ | Add effective address calculation time | |
n | Is the shift or rotate count |