NuMicro® NUC029LEE/NUC029SEE
32-bit Arm
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Cortex
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-M0 Microcontroller
Aug, 2018
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LIN header time-out error
The LIN slave controller contains a header time-out counter. If the entire header is not received
within the maximum time limit of 57 bit times, the header error flag LINS_HERR_F (UA_LIN_SR
[1]) will be set. The time-out counter is enabled at each break detect edge and stopped in the
following conditions.
A LIN frame ID field has been received.
The header error flag asserts.
Writing 1 to the LINS_SYNC_F (UA_LIN_SR[3]) to re-search a new frame header.
Mute mode and LIN exit from mute mode condition
In Mute mode, a LIN slave node will not receive any data until specified condition occurred. It
allows header detection only and prevents the reception of any other characters. User can enable
Mute mode by setting the LIN_MUTE_EN (UA_LIN_CTL[4]) and exiting from Mute mode
condition can be selected by LIN_HEAD_SEL (UA_LIN_CTL[23:22]).
Note:
It is recommended to set LIN slave node to Mute mode after checksum transmission.
The LIN slave controller exiting from Mute mode is described as follows: If LIN_HEAD_SEL
(UA_LIN_CTL[23:22]) is set to
“break field”, when LIN slave controller detects a valid LIN break +
delimiter, the controller will enable the receiver (exit from Mute mode) and subsequent data (sync
data, frame ID data, response data) are received in RX-FIFO.
If LIN_HEAD_SEL (UA_LIN_CTL[23:22]) is set to
“break field and sync field”, when the LIN slave
controller detects a valid LIN break + delimiter followed by a valid sync field without frame error,
the controller will enable the receiver (exit from mute mode) and subsequent data(ID data,
response data) are received in RX-FIFO. If LIN_HEAD_SEL (UA_LIN_CTL[23:22]) is set to
“break
field, sync field and ID field”, when the LIN slave controller detects a valid LIN break + delimiter
and valid sync field without frame error followed by ID data without frame error and received ID
data matched LIN_PID (UA_LIN_CTL[31:24]) value. The controller will enable the receiver (exit
from mute mode) and subsequent data (response data) are received in RX-FIFO.
Slave mode non-automatic resynchronization
User can disable the automatic resynchronization function to fix the communication baud rate.
When operating in Non-Automatic Resynchronization mode, software needs some initial process,
and the initialization process flow of Non-Automatic Resynchronization mode is shown as follows:
1. Select the desired baud rate by setting the UA_BAUD register.
2. Select LIN function mode by setting UA_FUN_SEL (UA_FUN_SEL[1:0]) to
‘01’.
3. Disable automatic resynchronization function by setting LINS_ARS_EN (UA_LIN_CTL[2]) is
set to 0.
4. Enable LIN slave mode by setting the LINS_EN (UA_LIN_CTL[0]) is set to 1.
