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Data Shift Instructions Section 3-9
Description ROL(027) shifts all bits of Wd including the Carry Flag (CY) to the left (from
rightmost bit to leftmost bit).
Flags
Precautions When ROL(027) is executed, the Error Flag will turn OFF.
If as a result of the shift the contents of Wd is zero, the Equals Flag will turn
ON.
If as a result of the shift the contents of the leftmost bit of Wd is 1, the Nega-
tive Flag will turn ON.
Note It is possible to set the Carry Flag contents to 1 or 0 immediately before exe-
cuting this instruction, by using the Set Carry (STC(040)) or Clear Carry
(CLC(041)) instructions.
Examples When CIO 000000 is ON, word CIO 0100 and the Carry Flag (CY) will shift
one bit to the left. The contents of CIO 010015 will be shifted to the Carry Flag
(CY) and the Carry Flag contents will be shifted to CIO 010000.
Indirect DM/EM
addresses in binary
@ D00000 to @ D32767
@ E00000 to @ E32767
@ En_00000 to @ En_32767
(n = 0 to C)
Indirect DM/EM
addresses in BCD
*D00000 to *D32767
*E00000 to *E32767
*En_00000 to *En_32767
(n = 0 to C)
Constants ---
Data Registers DR0 to DR15
Index Registers ---
Indirect addressing
using Index Registers
,IR0 to ,IR15
–2048 to +2047 ,IR0 to –2048 to +2047 ,IR15
DR0 to DR15, IR0 to IR15
,IR0+(++) to ,IR15+(++)
,–(– –)IR0 to, –(– –)IR15
Area Wd
Name Label Operation
Error Flag ER OFF
Equals Flag = ON when the shift result is 0.
OFF in all other cases.
Carry Flag CY ON when 1 is shifted into the Carry Flag (CY).
OFF in all other cases.
Negative Flag N ON when the leftmost bit is 1 as a result of the shift.
OFF in all other cases.
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