RL78/D1A User's Manual: Hardware - Renesas

Under development
Preliminary document
Specifications in this document are tentative and subject to change.
RL78/D1A CHAPTER 13 ASYNCHRONOUS SERIAL INTERFACE LIN-UART (UARTF)
(17) LIN-UARTn buffer control register (UFnBUCTL)
The UFnBUCTL register is a 16-bit register that controls a buffer.
This register can be read or written in 16-bit units.
See 13.6.1 UART buffer mode transmission and 13.7 LIN Communication Automatic Baud Rate Mode for
details.
Reset input sets this register to 0000H.
Figure 13-17. Format of LIN-UARTn Buffer Control Register (UFnBUCTL) (1/2)
Address: F0258H, F0259H (UF0BUCTL), F0278H, F0279H (UF1BUCTL) After reset: 0000H R/W
15 14 13 12 11 10 9 8
UFnBUCTL 0 0 0 0 0 0 UFnTW UFnCON
(n = 0, 1) 7 6 5 4 3 2 1 0
UFnECS UFnNO UFnRRQ UFnTRQ UFnBUL3 UFnBUL2 UFnBUL1 UFnBUL0
UFnTW Transmission start wait bit
0 Starts transmission immediately when buffer data transmission is requested.
1 Delays starting of transmission until completion of stop bit of reception when buffer
data transmission is requested.
The UFnTW bit is used to delay starting of transmission until completion of the stop bit of reception
when transmitting buffer data in LIN communication. It can be set only in automatic baud rate mode
(UFnMD1, UFnMD0 = 11B). See 13.5.11 Transmission start wait function and 13.7 LIN
Communication Automatic Baud Rate Mode for details.
Cautions 1. Setting this bit is prohibited except when switching to response transmission
after header reception.
2. The UFnTW bit becomes valid at the same time as the UFnTRQ bit is set (1).
UFnCON Successive selection bit
0 The data group to be transmitted or received next is the last data group.
1 The data group to be transmitted or received next is not the last data group.
(Data transmission or reception is continued without waiting for the next header to be
received.)
The UFnCON bit indicates that the data group to be transmitted or received next is not the last data
group when the multi-byte response transmission/reception function is used in LIN communication.
It can be set only in automatic baud rate mode (UFnMD1, UFnMD0 = 11B).
See 13.7.5 Multi-byte response transmission/reception function for details.
Cautions 1. Setting this bit is prohibited except when the multi-byte transmission/reception
function is used.
2. Set the UFnCON bit at the same time as setting UFnNO, UFnRRQ, and UFnTRQ
for 16-bit access.
UFnECS Enhanced checksum selection bit
0 Classic checksum (used only for data byte calculation)
1 Enhanced checksum (used for calculating data byte + PID byte)
The UFnECS bit is used to select how to handle checksum when the automatic checksum function
is used in LIN communication. It is valid only when in automatic baud rate mode (UFnMD1,
UFnMD0 = 11B) and automatic checksum is enabled (UFnACE = 1).
See 13.7.4 Automatic checksum function for details.
R01UH0317EJ0004 Rev. 0.04 711
Feb. 22, 2013