
R8C/3GM Group
26. Hardware LIN
R01UH0284EJ0100 Rev.1.00
Aug 09, 2011
26.4.2
Slave Mode
Figure 26.8 show examples of Header Field Reception Flowchart.
During header field reception, the hardware LIN operates as follows:
(1) When 1 is written to the LSTART bit in the LINCR register for the hardware LIN, Synch Break detection is
enabled.
(2) If a “L” level is input for a duration equal to or longer than the period set in timer RA, the hardware LIN
detected it as a Synch Break. At this time, the SBDCT flag in the LINST register is set to 1. If the SBIE bit
in the LINCR register is set to 1, a timer RA interrupt is generated. Then the hardware LIN enters the Synch
Field measurement.
(3) The hardware LINA receives a Synch Field (55h) and measures the period of the start bit and bits 0 to 6 is
using timer RA. At this time, whether to input the Synch Field signal to RXD0 of UART0 can be selected
by the SBE bit in the LINCR register.
(4) When the Synch Field measurement is completed, the SFDCT flag in the LINST register is set to 1. If the
SFIE bit in the LINCR register is set to 1, a timer RA interrupt is generated.
(5) After the Synch Field measurement is completed, a transfer rate is calculated from the timer RA count
value. The rate is set in UART0 and registers TRAPRE and TRA for timer RA are set again. Then the
hardware LIN receives an ID field via UART0.
(6) After the hardware LIN completes receiving the ID field, it performs communication for a response field.
Figure 26.5
Operating Example during Header Field Reception
RXD0 pin
Synch Break
RXD0 input
for UART0
RXDSF flag in
LINCR register
Synch Field
IDENTIFIER
(2)
(3)
(5)
(6)
The above applies when:
LINE = 1, MST = 0, SBE = 1, SBIE = 1, SFIE = 1
(4)
(1)
SBDCT flag in
LINST register
SFDCT flag in
LINST register
IR bit in
TRAIC register
1 is written to B0CLR bit
in LINST register.
This period is measured.
1 is written to B1CLR bit
in LINST register.
Set to 0 when an interrupt request is acknowledged
or by a program.
1 is written to LSTART bit
in LINCR register.
The flag is set to 0 after Synch Field
measurement is completed.