Table of Contents
Advertisement
14.5.8 SBF transmission/reception (UART0 only)
The UART0 of the V850ES/KE1+ 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.
(1) SBF transmission/reception format
Figures 14-12 and 14-13 outline the transmission and reception manipulations of LIN.
Wakeup
signal frame
LIN bus
Note 1
8 bits
TXD0 (output)
INTST0
interrupt
Notes 1.
80H transfer in the 8-bit mode is substituted for the wakeup signal frame.
2.
SBF output is performed by hardware. The output width is the bit length set by the ASICL0.SBL02
to ASICL0.SBL00 bits. If even finer output width adjustments are required, such adjustments can
be performed using the value of BRG (refer to 14.6 Dedicated Baud Rate Generator n (BRGn)).
3.
A transmission completion interrupt request signal (INTST0) is output at the start of each
transmission. The INTST0 signal is also output at the start of each SBF transmission.
Remark
The interval between each field is controlled by software.
420
CHAPTER 14 ASYNCHRONOUS SERIAL INTERFACE (UART)
Figure 14-12. LIN Transmission Manipulation Outline
Sync
break field
Note 2
transmission
13 bits
Note 3
SBF transmission
User's Manual U16896EJ2V0UD
Sync
Ident
Data
field
field
field
55H
Data
Data
transmission
transmission
Checksum
Data
field
field
Data
Data
transmission
transmission
Advertisement
Table of Contents
