ST72561J9-Auto STMicroelectronics, ST72561J9-Auto Datasheet - Page 182

• Manufacturer Part Number: ST72561J9-Auto
• Description: 8-bit MCU for automotive
• Manufacturer: STMicroelectronics

Specifications of ST72561J9-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years at 55 °C
• 5 Power Saving Modes: halt, auto wake up from halt, active halt, wait and slow

LINSCI serial communication interface (LIN master/slave)
15.9.5
15.9.6
Note:
Note:
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LIN baud rate
Baud rate programming is done by writing a value in the LPR prescaler or performing an
automatic resynchronization as described below.
Automatic resynchronization
To automatically adjust the baud rate based on measurement of the LIN synch field:
●
●
When auto synchronization is enabled, after each LIN synch break, the time duration
between five falling edges on RDI is sampled on f
stored in an internal 15-bit register called SM (not user accessible) (see
the LDIV value (and its associated LPFR and LPR registers) are automatically updated at
the end of the fifth falling edge. During LIN synch field measurement, the SCI state machine
is stopped and no data is transferred to the data register.
LIN slave baud rate generation
In LIN mode, transmission and reception are driven by the LIN baud rate generator
LIN master mode uses the extended or conventional prescaler register to generate the baud
rate.
If LINE bit = 1 and LSLV bit = 1 then the conventional and extended baud rate generators
are disabled: the baud rate for the receiver and transmitter are both set to the same value,
depending on the LIN slave baud rate generator:
with:
LDIV is an unsigned fixed point number. The mantissa is coded on 8 bits in the LPR register
and the fraction is coded on 4 bits in the LPFR register.
If LASE bit = 1 then LDIV is automatically updated at the end of each LIN synch field.
Three registers are used internally to manage the auto-update of the LIN divider (LDIV):
●
●
●
The control and interactions of these registers is explained in
depends on the LDUM bit setting (LIN divider update method)
As explained in
transfer from LDIV_MEAS at the end of the LIN sync field and a transfer from LDIV_NOM
due to a software write of LPR. If both operations occur at the same time, the transfer from
LDIV_NOM has priority.
Write the nominal LIN prescaler value (usually depending on the nominal baud rate) in
the LPFR / LPR registers.
Set the LASE bit to enable the auto synchronization unit.
LDIV_NOM (nominal value written by software at LPR/LPFR addresses)
LDIV_MEAS (results of the field synch measurement)
LDIV (used to generate the local baud rate)
Tx = Rx =
Figure 84
(16
f
CPU
*
LDIV)
and
Doc ID 12370 Rev 8
Figure
85, LDIV can be updated by two concurrent actions: a
CPU
and the result of this measurement is
Figure 84
and
Figure
Figure
ST72561-Auto
83). Then
85. It