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X-Hacker.org- CA-Clipper Tools . Books 1-3 - <b>com_lsr()</b>
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COM_LSR()
Reads the Line Status Register (LSR)
------------------------------------------------------------------------------
Syntax
COM_LSR(<nComPort>) --> nLSR
Argument
<nComPort> Designates the port (1 to 4) that reads the Line Status
Register (LSR).
Returns
COM_LSR() returns the contents of the Line Status Register.
Description
The Line Status Register makes the following information available:
Table 3-3: LS Register Coding
------------------------------------------------------------------------
Bit Symb. Const Definition
------------------------------------------------------------------------
0 LSR_ERROR Parameter error
1 LSR_DATA_READY Data ready
2 LSR_OVERRUN_ERR Overflow error
4 LSR_PARITY_ERR Parity error
8 LSR_FRAMING_ERR Framing error
16 LSR_BREAK BREAK recognized
32 LSR_TRANS_HOLD_EMPTY Transmission holder register empty
64 LSR_TRANS_EMPTY TX shift register empty
------------------------------------------------------------------------
Notes
. The Line Status Register can only be examined using this
function.
. Some bits in this register are reset by a read.
Example
nStatus := COM_LSR(2) // Read LSR port 2
IF ISBIT(nStatus, 5) // Set bit 5
? "BREAK recognized - Abort!"
ENDIF
See Also: COM_MCR() COM_MSR()
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