RL78/G13 CHAPTER 12 SERIAL ARRAY UNIT
R01UH0146EJ0100 Rev.1.00 641
Sep 22, 2011
12.6.1 UART transmission
UART transmission is an operation to transmit data from the RL78/G13 to another device asynchronously (start-stop
synchronization).
Of two channels used for UART, the even channel is used for UART transmission.
UART UART0 UART1 UART2 UART3
Target channel Channel 0 of SAU0 Channel 2 of SAU0 Channel 0 of SAU1 Channel 2 of SAU1
Pins used TxD0 TxD1 TxD2 TxD3
INTST0 INTST1 INTST2 INTST3 Interrupt
Transfer end interrupt (in single-transfer mode) or buffer empty interrupt (in continuous transfer mode)
can be selected.
Error detection flag None
Transfer data length 7, 8, or 9 bits
Note 1
Transfer rate Max. fMCK/6 [bps] (SDRmn [15:9] = 3 or more), Min. fCLK/(2 × 2
15
× 128) [bps]
Note 2
Data phase Forward output (default: high level)
Reverse output (default: low level)
Parity bit The following selectable
• No parity bit
• Appending 0 parity
• Appending even parity
• Appending odd parity
Stop bit The following selectable
• Appending 1 bit
• Appending 2 bits
Data direction MSB or LSB first
Notes 1. Only following UARTs can be specified for the 9-bit data length.
• 24 to 64-pin products: UART0
• 80, 100, 128-pin products: UART0 and UART2
2. Use this operation within a range that satisfies the conditions above and the AC characteristics in the
electrical specifications (see CHAPTER 29 ELECTRICAL SPECIFICATIONS).
Remarks 1. f
MCK: Operation clock frequency of target channel
f
CLK: System clock frequency
2. m: Unit number (m = 0, 1), n: Channel number (n = 0, 2), mn = 00, 02, 10, 12
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