2 bit reset (bc) – HEIDENHAIN TNC 407 (243 020) Technical Manual User Manual
Page 558
3.10.2 BIT RESET (BC)
Abbreviation for PLC Editor:
BC (BIT CLEAR)
Byte/Word/Double
Constant
Execution time [µs]
0.5 to 0.8
0.3 to 0.4
Number of bytes
6
8
Operands: B, W, D, K
Operation:
With this command, each bit in the Accumulator can be acted on. The addressed bit is set to "0"
through the use of the BC command. The selection (addressing) of the corresponding bit is derived
from the content of the specified Operand or a Constant. In the bit-numbering, bit 0 corresponds to
the LSB and bit 31 the MSB. For operand contents larger than 32, the operand value Modulo 32 is
used, i.e. the integer remainder from the division (operand value)/32.
Example:
Load Doubleword D8 in the Accumulator, set bit 0 of the Accumulator to "0" and store the result in
Doubleword D12.
Initial state:
Doubleword D8 = 3E 81 (hex)
Doubleword D12 = ?
Accumulator and operand contents are shown here in hexadecimal notation.
Line Instruction
Accumulator Content
Operand Content
xx
xx
xx
xx
1
L D8
00
00
3E
81
00
00
3E
81
2
BC K+0
00
00
3E
80
3
= D12
00
00
3E
80
00
00
3E
80
Line 1:
Load Doubleword D8 into the Accumulator.
Line 2:
The bit specified in the operand is set to "0".
Line 3:
The result is stored in Doubleword D12.