NEC 78K0S/KB1+ User Manual page 181

signal frame
LIN bus
RX6 Disable
Reception interrupt
(INTSR6)
<1>
Edge detection
(INTP0)
Capture timer
<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 request 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 request signal is not output and the SBF reception mode is
restored.
<3> If SBF reception has been completed correctly, an interrupt request signal is output.
timer/event counter 00 during SBF reception completion interrupt processing, and measure the bit width
(pulse width) of the sync field (refer to 6.4.3 Pulse width measurement operations). Detection of errors
OVE6, PE6, and FE6 is 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 synchronous 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 11-3 illustrates 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 synchronous 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 signal of the reception port input (RxD6) can be input to the external interrupt (INTP0) and 16-bit
timer/event counter 00 by port input switch control (ISC0/ISC1), without connecting RxD6 and INTP0/TI000 externally.
CHAPTER 11 SERIAL INTERFACE UART6
Figure 11-2. LIN Reception Operation
Wakeup Synchronous
break field
13 bits
SBF reception
<2>
Enable
<3>
Disable
User's Manual U17446EJ3V1UD
Synchronous Identifier Data field
field field
SF ID
reception reception reception
<4>
Enable
Data field Checksum
field
Data Data Data
reception reception
<5>
Start the 16-bit
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