NEC 78K0 Series User Manual page 349

signal frame
LIN Bus
R D6
X
Disable
(input)
Reception interrupt
(INTSR6)
<1>
Edge detection
(INTP0)
Capture timer
Reception processing is as follows.
<1> The wakeup signal is detected at the edge of the pin, and enables UART6 and sets the SBF reception
mode.
<2> Reception continues until the STOP bit is detected. When an SBF with low-level data of 11 bits or more has
been detected, it is assumed that SBF reception has been completed correctly, and an interrupt signal is
output. If an SBF with low-level data of less than 11 bits has been detected, it is assumed that an SBF
reception error has occurred. The interrupt signal is not output and the SBF reception mode is restored.
<3> If SBF reception has been completed correctly, an interrupt signal is output. Start 16-bit timer/event counter
00 by the SBF reception end interrupt servicing and measure the bit interval (pulse width) of the sync field
(see 7.4.8 Pulse width measurement operation).
suppressed, and error detection processing of UART communication and data transfer of the shift register
and RXB6 is not performed. The shift register holds the reset value FFH.
<4> Calculate the baud rate error from the bit interval of the sync field, disable UART6 after SF reception, and
then re-set baud rate generator control register 6 (BRGC6).
<5> Distinguish the checksum field by software. Also perform processing by software to initialize UART6 after
reception of the checksum field and to set the SBF reception mode again.
Figure 15-3 shows the port configuration for LIN reception operation.
The wakeup signal transmitted from the LIN master is received by detecting the edge of the external interrupt
(INTP0). The length of the sync field transmitted from the LIN master can be measured using the external event
capture operation of 16-bit timer/event counter 00, and the baud rate error can be calculated.
The input source of the reception port input (R
timer/event counter 00 by port input switch control (ISC0/ISC1), without connecting R
CHAPTER 15 SERIAL INTERFACE UART6
Figure 15-2. LIN Reception Operation
Wakeup Sync
break field
13-bit
SBF reception
<2>
Enable
<3>
Disable
D6) can be input to the external interrupt (INTP0) and 16-bit
X
Preliminary User's Manual U17260EJ3V1UD
Sync field Identifier Data field
field
SF ID Data
reception reception reception
<4>
Enable
Detection of errors OVE6, PE6, and FE6 is
D6 and INTP0/TI000 externally.
X
Data field Checksum
field
Data Data
reception reception
<5>
349