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SYNTAX      [<LABEL>] STXM

OPERANDS    None

EXECUTION   (PC) + 1 . PC
            1 . TXM status bit in status register ST1
            Affects TXM.

DESCRIPTION The STXM instruction sets the TXM status bit to logic one
            which configures the serial port transmit section to a mode
            where the FSX pin behaves as an output. A pulse is produced
            on the FSX pin each time the DXR register is loaded
            internally. The transmission is initiated by the negative edge
            of this pulse. TXM may also be loaded by the LST1 and RTXM
            instructions. If the FSM status bit is a logic zero and serial
            port operation has already started, the FSX pin will be driven
            low if TXM = 1.

WORDS       1

ENCODING    15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
            +-----------------------------------------------+
            |1  1  0  0  1  1  1  0  0  0  1  0  0  0  0  1 |
            +-----------------------------------------------+

CYCLES

            +------------------------------------------------+
            |    Cycle Timings for a Single Instruction      |
            |------------------------------------------------|
            | PI/DI | PI/DE | PE/DI | PE/DE  | PR/DI | PR/DE |
            |-------+-------+-------+--------+-------+-------|
      '20   |   1   |   1   |  1+p  |  1+p   |   -   |   -   |
            |-------+-------+-------+--------+-------+-------|
     'C25   |   1   |   1   |  1+p  |  1+p   |   1   |   1   |
            |------------------------------------------------|
            |    Cycle Timings for a Repeat Instruction      |
            |------------------------------------------------|
      '20   |   n   |   n   |  n+p  |  n+p   |   -   |   -   |
            |-------+-------+-------+--------+-------+-------|
     'C25   |   n   |   n   |  n+p  |  n+p   |   n   |   n   |
            +------------------------------------------------+



EXAMPLE     STXM              TXM is set, configuring FSX as an output.