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RL78/G1P
CHAPTER 11 SERIAL ARRAY UNIT
R01UH0895EJ0100 Rev.1.00
432
Nov 29, 2019
11.7 Operation of UART (UART0) Communication
This is a start-stop synchronization function using two lines: serial data transmission (T
X
D) and serial data reception
(R
X
D) lines. By using these two communication lines, each data frame, which consist of a start bit, data, parity bit, and
stop bit, is transferred asynchronously (using the internal baud rate) between the microcontroller and the other
communication party. Full-duplex asynchronous communication UART communication can be performed by using a
channel dedicated to transmission (even-numbered channel) and a channel dedicated to reception (odd-numbered
channel).
[Data transmission/reception]
Data length of 7, 8, or 9 bits
Select the MSB/LSB first
Level setting of transmit/receive data (selecting whether to reverse the level)
Parity bit appending and parity check functions
Stop bit appending, stop bit check function
[Interrupt function]
Transfer end interrupt/buffer empty interrupt
Error interrupt in case of framing error, parity error, or overrun error
[Error detection flag]
Framing error, parity error, or overrun error
In addition, UART0 reception supports the SNOOZE mode. When RxD0 pin input is detected while in the STOP mode,
the SNOOZE mode makes data reception that does not require the CPU possible.