Datasheet

RL78/L12 CHAPTER 12 SERIAL ARRAY UNIT
R01UH0330EJ0200 Rev.2.00 511
Dec 13, 2013
Figure 12-98. Reception Operation of LIN
LIN Bus
BF reception
SF
reception
ID
reception
Data
reception
Data
reception
Data
reception
Wakeup signal
frame
Break field
Sync field Identification
field
Data filed Data filed Checksum
field
R
XD0
INTSR0
Edge detection
(INTP0)
TM05
<1>
<2>
<3> <4>
<5>
STOP Pulse interval measurement Pulse width measurementPulse width measurement
UART0
INTTM05
Reception stopSTOP
Message header Message
Here is the flow of signal processing.
<1> The wakeup signal is detected by detecting an interrupt edge (INTP0) on a pin. When the wakeup signal is
detected, change TM05 to pulse width measurement upon detection of the wakeup signal to measure the low-
level width of the BF signal. Then wait for BF signal reception.
<2> TM05 starts measuring the low-level width upon detection of the falling edge of the BF signal, and then captures
the data upon detection of the rising edge of the BF signal. The captured data is used to judge whether it is the
BF signal.
<3> When BF reception has been correctly completed, start channel 5 of the timer array unit and measure the bit
interval (pulse width) of the sync field (see 6.8.4 Operation as input pulse interval measurement).
<4> Calculate a baud rate error from the bit interval of sync field (SF). Stop UART0 once and adjust (re-set) the baud
rate.
<5> The checksum field should be distinguished by software. In addition, processing to initialize UART0 after the
checksum field is received and to wait for reception of BF should also be performed by software.