GE PACSystems RX7i, Cpu Programmer'S Reference Manual

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Chapter 5. Function Block Diagram (FBD)
238 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
5.3 Bit Operation Functions
The Bit Operation functions perform comparison, logical, and move operations on bit strings. Bit
Operation functions treat each WORD or DWORD data as a continuous string of bits, with bit 1 of the
WORD or DWORD being the Least Significant Bit (LSB). The last bit of the WORD or DWORD is the
Most Significant Bit (MSB).
Warning
Overlapping input and output reference address ranges
in multiword functions is not recommended, as it can
produce unexpected results.
Function Description
Logical AND. Compares the bit strings IN1 and IN2 bit by bit. When the corresponding bits
are both 1, places a 1 in the corresponding location in output string Q; otherwise, places a
0 in the corresponding location in Q.
If additional inputs (IN3 through IN8) are used, each additional bit string is compared to the
string in Q and the result is placed in Q.
For details, refer to
Logical AND
.
Logical OR. Compares the bit strings IN1 and IN2 bit by bit. When a pair of corresponding
bits are both 0, places a 0 in the corresponding location in output string Q; otherwise,
places a 1 in the corresponding location in Q.
If additional inputs (IN3 through IN8) are used, each additional bit string is compared to the
string in Q and the result is placed in Q.
For details, refer to
Logical OR
.
Logical XOR. Compares the bit strings IN1 and IN2 bit by bit. When a pair of corresponding
bits are different, places a 1 in the corresponding location in the output bit string Q; when a
pair of corresponding bits are the same, places a 0 in Q.
If additional inputs (IN3 through IN8) are used, each additional bit string is compared to the
string in Q and the result is placed in Q.
For details, refer to
Logical XOR
.
Logical NOT. Sets the state of each bit in output bit string Q to the opposite state of the
corresponding bit in bit string IN1.
For details, refer to
Logical NOT
.
Rotate Bits Left. Rotates all the bits in a string a specified number of places to the left.
For details, refer to
Bit Operation Functions in Chapter 4.