
CHAPTER 15 ASYNCHRONOUS SERIAL INTERFACE A (UARTA)
User’s Manual U17790EJ2V0UD
518
15.6.2 SBF transmission/reception format
The V850ES/SJ3 has an SBF (Sync Break Field) transmission/reception control function to enable use of the LIN
function.
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 15-6 and 15-7 outline the transmission and reception manipulations of LIN.
Figure 15-6. LIN Transmission Manipulation Outline
LIN
bus
Wake-up
signal
frame
Sync
break
field
Sync
field
Identifier
field
DATA
field
DATA
field
Check
SUM
field
INTUAnT
interrupt
TXDAn (output)
Note 3
8 bits
Note 1
Note 2
13 bits
SBF transmission
Note 4
55H
transmission
Data
transmission
Data
transmission
Data
transmission
Data
transmission
Notes 1. The interval between each field is controlled by software.
2. SBF output is performed by hardware.
The output width is the bit length set by the
UAnOPT0.UAnSLSL2 to UAnOPT0.UAnSLS0 bits.
If even finer output width adjustments are
required, such adjustments can be performed using the UAnCTLn.UAnBRS7 to UAnCTLn.UAnBRS0
bits.
3. 80H transfer in the 8-bit mode is substituted for the wakeup signal frame.
4. A transmission enable interrupt request signal (INTUAnT) is output at the start of each transmission.
The INTUAnT signal is also output at the start of each SBF transmission.