
R8C/36T-A Group
22. Hardware LIN
Under development Preliminary document
Specifications in this document are tentative and subject to change.
R01UH0240EJ0010 Rev.0.10
Page 528 of 728
Aug 05, 2011
22.4.2
Slave Mode
show Examples of Header Field Reception Flowchart.
During header field reception, the hardware LIN operates as follows:
(1) When 1 (timer RJ input enabled, RXD input disabled) is written to the LSTART bit in the LINCT register
of the hardware LIN, Synch Break detection is enabled.
(2) If a low level is input for a duration equal to or longer than the period set in timer RJ, the hardware LIN
detects it as a Synch Break. At this time, the SBDCT bit in the LINST register is set to 1 (Synch Break is
detected or Synch Break generation is completed). If the SBIE bit in the LINCT register is set to 1 (Synch
Break detection interrupt enabled), a timer RJ interrupt is generated. Then the hardware LIN enters Synch
Field measurement.
(3) The hardware LIN receives a Synch Field (55h) and measures the period of the start bit and bits 0 to 6
using timer RJ. At this time, whether or not to input the Synch Field signal to RXD of UART0 can be
selected by the SBE bit in the LINCT register.
(4) When Synch Field measurement is completed, the SFDCT flag in the LINST register is set to 1. If the
SFIE bit in the LINCT register is set to 1, a timer RJ interrupt is generated.
(5) After Synch Field measurement is completed, a transfer rate is calculated from the timer RJ count value.
The rate is set in UART0 and the TRJ register of timer RJ is 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 22.5
Operation Example during Header Field Reception
1 is written to
B1CLR bit in
LINST register
RXD pin
Synch Break
RXD input
for UART0
RXDSF bit in
LINCT register
Synch Field
IDENTIFIER
(2)
(3)
(5)
(6)
The above diagram applies under the following condition:
LINE = 1, MST = 0, SBE = 1, SBIE = 1, SFIE = 1
(4)
(1)
SBDCT bit in
LINST register
SFDCT bit in
LINST register
IR bit in
TRJIC register
1 is written to B0CLR
bit in LINST register
The flag is set to 0 after
Synch Field measurement
is completed.
Set to 0 by acknowledgment of an interrupt request
or by a program
1 is written to
LSTART bit in
LINCT register
This period is measured