MS51
Dec. 17, 2019
Page
244
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Rev 1.01
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Bit
Name
Description
3
TB8
9th transmitted bit
This bit defines the state of the 9th transmission bit in serial port 0 Mode 2 or 3. It is not used in
Mode 0 or 1.
2
RB8
9th received bit
The bit identifies the logic level of the 9th received bit in serial port 0 Mode 2 or 3. In Mode 1, RB8 is
the logic level of the received stop bit. SM2 bit as logic 1 has restriction for exception. RB8 is not
used in Mode 0.
1
TI
Transmission interrupt flag
This flag is set by hardware when a data frame has been transmitted by the serial port 0 after the
8th bit in Mode 0 or the last data bit in other modes. When the serial port 0 interrupt is enabled,
setting this bit causes the CPU to execute the serial port 0 interrupt service routine. This bit should
be cleared manually via software.
0
RI
Receiving interrupt flag
This flag is set via hardware when a data frame has been received by the serial port 0 after the 8th
bit in Mode 0 or after sampling the stop bit in Mode 1, 2, or 3. SM2 bit as logic 1 has restriction for
exception. When the serial port 0 interrupt is enabled, setting this bit causes the CPU to execute to
the serial port 0 interrupt service routine. This bit should be cleared manually via software.