Renesas rl78 User Manual

RL78/G1A

CHAPTER 12 SERIAL ARRAY UNIT

R01UH0305EJ0200 Rev.2.00

502

Jul 04, 2013

12.6 Operation of UART (UART0 to UART2) Communication

This is a start-stop synchronization function using two lines: serial data transmission (T

D) and serial data reception

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 UART communication can be performed by using a channel dedicated to transmission

(even-numbered channel) and a channel dedicated to reception (odd-numbered channel). The LIN-bus can be

implemented by using UART2, timer array unit o (channel 0) with an external interrupt (INTP0).

[Data transmission/reception]

• Data length of 7, 8, or 9 bits

Note

• 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 (channel 1 of unit 0) 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. Only following

UART0 can be specified for the reception baud rate adjustment function.

The LIN-bus is accepted in UART2 (channels 0 and 1 of unit 1) (32, 48, and 64-pin products only).

[LIN-bus functions]

• Wakeup signal detection
• Break field (BF) detection
• Sync field measurement, baud rate calculation

Note Only following UART0 can be specified for the 9-bit data length.

Using the external interrupt (INTP0) and

timer array unit 0 (channel 7)

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