33912 Datasheet, PDF (38/47 Pages) Freescale Semiconductor, Inc – LIN System Basis Chip with DC Motor Pre-driver and Current

FUNCTIONAL DEVICE OPERATIONS
LOGIC COMMANDS AND REGISTERS
LIN Control Register - LINCR
This register controls the LIN physical interface block.
Writing the LIN Control Register (LINCR) returns the LIN
Status Register (LINSR).
Table 14. LIN Control Register - $4
C3
C2
C1
C0
Write
LDVS
RXONLY
LSR1
LSR0
Reset
Value
0
0
0
0
Reset
Condition
POR, Reset
Mode or
ext_reset
POR, Reset
Mode, ext_reset
or LIN failure
gone*
POR
* LIN failure gone: if LIN failure (overtemp, TXD/RXD short) was set, the flag
resets automatically when the failure is gone.
LDVS - LIN Dominant Voltage Select
This write-only bit controls the LIN Dominant voltage:
1 = LIN Dominant Voltage = V_{LIN_DOM_1} (1.7V typ)
0 = LIN Dominant Voltage = V_{LIN_DOM_0} (1.1V typ)
RXONLY - LIN Receiver Operation Only
This write-only bit controls the behavior of the LIN
transmitter.
In Normal Mode, the activation of the RXONLY bit disables
the LIN transmitter. In case of a LIN error condition, this bit is
automatically set.
In Stop Mode this bit disables the LIN wake-up
functionality, and the RXD pin will reflect the state of the LIN
bus.
1 = only LIN receiver active (Normal Mode) or LIN wake-
up disabled (Stop Mode).
0 = LIN fully enabled.
LSRx - LIN Slew-Rate
This write-only bit controls the LIN driver slew-rate in
accordance with Table 15.
Table 15. LIN Slew-Rate Control
LSR1 LSR0
Description
0
0
0
1
1
0
1
1
Normal Slew Rate (up to 20kb/s)
Slow Slew Rate (up to 10kb/s)
Fast Slew Rate (up to 100kb/s)
Reserved
LIN Status Register - LINSR
This register returns the status of the LIN physical
interface block and is also returned when writing to the
LINCR.
Table 16. LIN Status Register - $4/$5
S3
S2
S1
S0
Read RXSHORT TXDOM
LINOT
LINOC
RXSHORT - RXD Pin Short-Circuit
This read-only bit indicates a short-circuit condition on the
RXD pin (shorted either to 5.0V or to Ground). The short-
circuit delay must be a worst case of 8µs to be detected and
to shut down the driver. To clear this bit, it must be read after
the condition is gone (transition detected on RXD pin). The
LIN driver is automatically re-enabled once the condition is
gone.
1 = RXD short-circuit condition.
0 = None.
TXDOM - TXD Permanent Dominant
This read-only bit signals the detection of a TXD pin stuck
at dominant (Ground) condition and the resultant shutdown in
the LIN transmitter. This condition is detected after the TXD
pin remains in dominant state for more than 1 second (typical
value).
To clear this bit, it must be read after TXD has gone high.
The LIN driver is automatically re-enabled once TXD goes
High.
1 = TXD stuck at dominant fault detected.
0 = None.
LINOT - LIN Driver Over-temperature Shutdown
This read-only bit signals that the LIN transceiver was
shutdown due to over-temperature. The transmitter is
automatically re-enabled after the over-temperature
condition is gone and TXD is high. The LINOT bit is cleared
after SPI read once the condition is gone.
1 = LIN over-temperature shutdown
0 = None
LINOC - LIN Driver Over-Current Shutdown
This read-only bit signals an over-current condition
occurred on the LIN pin. The LIN driver is not shut down but
an IRQ is generated. To clear this bit, it must be read after the
condition is gone.
1 = LIN over-current shutdown
0 = None
33912
38
Analog Integrated Circuit Device Data
Freescale Semiconductor