Datasheet

78K0/Ix2 CHAPTER 14 SERIAL INTERFACE UART6/DALI
R01UH0010EJ0500 Rev.5.00 427
Feb 28, 2012
Cautions 3. Set POWER6 = 1 and then set TXE6 = 1 (transmission) or RXE6 = 1 (reception) to start
communication.
4. TXE6 and RXE6 are synchronized by the base clock (f
XCLK6) set by CKSR6. To enable
transmission or reception again, set TXE6 or RXE6 to 1 at least two clocks of the base clock
after TXE6 or RXE6 has been cleared to 0. If TXE6 or RXE6 is set within two clocks of the base
clock, the transmission circuit or reception circuit may not be initialized.
5. Set transmit data to TXB6 at least one base clock (f
XCLK6) after setting TXE6 = 1.
6. If data is continuously transmitted, the communication timing from the stop bit to the next start
bit is extended two operating clocks of the macro. However, this does not affect the result of
communication because the reception side initializes the timing when it has detected a start bit.
Do not use the continuous transmission function if the interface is used in LIN communication
operation.
Remark LIN stands for Local Interconnect Network and is a low-speed (1 to 20 kbps) serial communication protocol
intended to aid the cost reduction of an automotive network.
LIN communication is single-master communication, and up to 15 slaves can be connected to one master.
The LIN slaves are used to control the switches, actuators, and sensors, and these are connected to the LIN
master via the LIN network.
Normally, the LIN master is connected to a network such as CAN (Controller Area Network).
In addition, the LIN bus uses a single-wire method and is connected to the nodes via a transceiver that
complies with ISO9141.
In the LIN protocol, the master transmits a frame with baud rate information and the slave receives it and
corrects the baud rate error. Therefore, communication is possible when the baud rate error in the slave is
15% or less.
Figures 14-1 and 14-2 outline the transmission and reception operations of LIN.
Figure 14-1. LIN Transmission Operation
LIN Bus
Wakeup
signal frame
8 bits
Note 1
55H
transmission
Data
transmission
Data
transmission
Data
transmission
Data
transmission
13-bit
Note 2
SBF
transmission
Sync
break field
Sync field Identifier
field
Data field Data field Checksum
field
TX6
(output)
INTST6
Note 3
Notes 1. The wakeup signal frame is substituted by 80H transmission in the 8-bit mode.
2. The sync break field is output by hardware. The output width is the bit length set by bits 4 to 2 (SBL62 to
SBL60) of asynchronous serial interface control register 6 (ASICL6) (refer to 14.4.2 (2) (h) SBF
transmission).
3. INTST6 is output on completion of each transmission. It is also output when SBF is transmitted.
Remark The interval between each field is controlled by software.