266
Shift Instructions
Section 5-17
5-17-8 ONE DIGIT SHIFT RIGHT – SRD(75)
Limitations
St and E must be in the same data area, and E must be less than or equal to
St.
DM 6144 to DM 6655 cannot be used for St or E.
Description
When the execution condition is OFF, SRD(75) is not executed. When the
execution condition is ON, SRD(75) shifts data between St and E (inclusive)
by one digit (four bits) to the right. 0 is written into the leftmost digit of St and
the rightmost digit of E is lost.
Precautions
If a power failure occurs during a shift operation across more than 50 words,
the shift operation might not be completed.
A 0 will be shifted into the most significant digit of St every cycle if the undiffer-
entiated form of SRD(75) is used. Use the differentiated form (@SRD(75)) or
combine SRD(75) with DIFU(13) or DIFD(14) to shift just one time.
Flags
ER:
The St and E words are in different areas, or St is less than E.
Indirectly addressed EM/DM word is non-existent.
(Content of
*
EM/
*
DM word is not BCD, or the EM/DM area boundary
has been exceeded.)
5-17-9 REVERSIBLE SHIFT REGISTER – SFTR(84)
Limitations
St and E must be in the same data area and St must be less than or equal
to E.
DM 6144 to DM 6655 cannot be used for C, St, or E.
Ladder Symbols
Operand Data Areas
SRD(75)
E
St
@SRD(75)
E
St
E
:
End word
IR, SR, AR, DM, EM, HR, LR
St
:
Starting word
IR, SR, AR, DM, EM, HR, LR
2
St
3
1
E
4 5
C
8
F
Lost data
0
...
C
:
Control word
IR, SR, AR, DM, EM, HR, LR
St
:
Starting word
IR, SR, AR, DM, EM, HR, LR
Ladder Symbols
Operand Data Areas
E
:
End word
IR, SR, AR, DM, EM, HR, LR
SFTR(84)
C
St
E
@SFTR(84)
C
St
E
