598
Table Data Processing Instructions Section 3-16
Applicable Program Areas
Operands C and C+1: Control words
C specifies the number of units (bytes or words) to be used in the FCS calcu-
lation. (Bit 13 of C+1 determines whether bytes or words are being used.)
When bit 13 of C+1 has been set to 1, FCS(180) calculates the FCS value for
bytes of data. In this case, bit 12 determines whether the calculation starts
with the rightmost byte of R1 (bit 12 = 1) or the leftmost byte of R1 (bit 12 = 0).
R1: First word in range
R1 specifies the first word in the range. The length of the range depends on
the number of units as well as the starting byte, if bytes are being used in the
calculation.
D: First destination word
The result of the calculation is output to D if bytes have been selected.
The result of the calculation is output to D+1 and D if words have been
selected. In this case, the leftmost four digits are stored in D+1 and the right-
most four digits are stored in D.
Operand Specifications
Block program areas Step program areas Subroutines Interrupt tasks
OK OK OK OK
15 0
C
15 014
0
C+1
13 12 11
0000 0000 000000
0
Calculation units
Number of words/bytes in range
Starting byte (Valid only when bit 13 is 1.)
0: Leftmost byte
1: Rightmost byte
0: Words
1: Bytes
R1
15 0
R1+(C units–1)
to
to
Calculation range
Area C R1 D
CIO Area CIO 0 to
CIO 6142
CIO 0 to CIO 6143
Work Area W0 to W510 W0 to W511
Holding Bit Area H0 to H510 H0 to H511
Auxiliary Bit Area A0 to A958 A0 to A959 A448 to A959
Timer Area T0000 to T4094 T0000 to T4095
Counter Area C0000 to C4094 C0000 to C4095
DM Area D0 to D32766 D0 to D32767
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