LAPIS Semiconductor ML62Q1000 Series, User Manual, Page: 455 / 882

ML62Q1000 Series User's Manual
Chapter 11 Serial Communication Unit
FEUL62Q1000 11-53
11.3.2.10 Receive Margin
If there is an error between the sender baud rate and the receiver baud rate generated by the baud rate generator, the error
accumulates until the last stop bit loading in one frame, decreasing the reception margin.
Figure 11-19 shows the baud rate errors and reception margin waveforms.
Figure 11-19 Baud Rate Errors and Reception Margin
[Note]
Ÿ
When designing the system, consider the difference of the baud rate between the transmission side and
reception side and delay of the start bit detection and adjust the baud rate in the UAn0BRT, UAn1BRT,
UAn0BRC, and UAn1BRC registers.
11.3.2.11 Note on usage of Half-duplex UART
When using the half-duplex UART and changing the transmission mode to receive mode, you must initialize and reconfigure
the channel as the receive mode after reset the channel of serial communication unit by Block Reset Control Register 2
(BRECON2). Notice that the reset by the BRECON2 register also resets other channel of the half-duplex UART.
Figure 11-20 shows the flow chart.
Figure 11-20 Flow chart for switching the transmission mode to the receive mode in Half-duplex UART mode
Sender baud rate is
slow (RXDn)
Sampling timing
UnRSS=1 UnRSS=0
Start
Start
Start Stop
Stop
Stop
Sender baud rate is
fast (RXDn)
Ideal waveform
(RXDn)
Set the corresponding bit of the BRECON2 to "1" to
reset the target channel and then reset the bit to
"0" to release the reset.
Run the UART receive mode
Initialize and reconfigure the
channel as the receive mode
UART transmission is completed
Reset the channel by Block Reset
Control Register 2 (BRECON2).