Shift And Rotate Instructions; Shift Right And Shift Left Instructions; Rotate Right And Rotate Left Instructions - Siemens Simatic S7-200 System Manual

Shift and Rotate Instructions

Shift Right and Shift Left Instructions

The Shift instructions shift the input value IN right or left by the shift
count N and load the result in the output OUT.
The Shift instructions fill with zeros as each bit is shifted out
shift count (N) is greater than or equal to the maximum allowed (8 for
byte operations, 16 for word operations, and 32 for double word
operations), the value is shifted the maximum number of times for
the operation. If the shift count is greater than 0, the overflow
memory bit (SM1.1) takes on the value of the last bit shifted out. The
zero memory bit (SM1.0) is set if the result of the shift operation is
zero.
Byte operations are unsigned. For word and double word
operations, the sign bit is shifted when you use signed data types.
Error conditions that set ENO = 0
H 0006 (indirect address)

Rotate Right and Rotate Left Instructions

The Rotate instructions rotate the input value (IN) right or left by the
shift count (N) and load the result in the memory location (OUT). The
rotate is circular.
If the shift count is greater than or equal to the maximum for the
operation (8 for a byte operation, 16 for a word operation, or 32 for a
double-word operation), the S7-200 performs a modulo operation on
the shift count to obtain a valid shift count before the rotation is
executed. This result is a shift count of 0 to 7 for byte operations, 0
to 15 for word operations, and 0 to 31 for double-word operations.
If the shift count is 0, a rotate operation is not performed. If the rotate
operation is performed, the value of the last bit rotated is copied to
the overflow bit (SM1.1).
If the shift count is not an integer multiple of 8 (for byte operations), 16 (for word operations), or 32 (for
double-word operations), the last bit rotated out is copied to the overflow memory bit (SM1.1). The zero
memory bit (SM1.0) is set when the value to be rotated is zero.
Byte operations are unsigned. For word and double word operations, the sign bit is shifted when you use
signed data types.
Error conditions that set ENO = 0
H 0006 (indirect address)
Table 6-58 Valid Operands for the Shift and Rotate Instructions
Inputs/Outputs Data Types
IN BYTE
WORD
DWORD
OUT BYTE
WORD
DWORD
N BYTE
.
SM bits affected:
H SM1.0 (zero)
H SM1.1 (overflow)
SM bits affected:
H SM1.0 (zero)
H SM1.1 (overflow)
Operands
IB, QB, VB, MB, SMB, SB, LB, AC, *VD, *LD, *AC, Constant
IW, QW, VW, MW, SMW, SW, T, C, LW, AC, AIW, *VD, *LD, *AC, Constant
ID, QD, VD, MD, SMD, SD, LD, AC, HC, *VD, *LD, *AC, Constant
IB, QB, VB, MB, SMB, SB, LB, AC, *VD, *LD, *AC
IW, QW, VW, MW, SMW, SW, T, C, LW, AC, *VD, *LD, *AC
ID, QD, VD, MD, SMD, SD, LD, AC, *VD, *LD, *AC
IB, QB, VB, MB, SMB, SB, LB, AC, *VD, *LD, *AC, Constant
S7-200 Instruction Set
If the
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