MC33910BAC / MC34910BAC
FUNCTIONAL DEVICE OPERATIONS
OPERATIONAL MODES
Over-current Shutdown (LIN Interrupt)
If the bit LINM is set in the interrupt mask register (IMR) an
interrupt IRQ will be generated.
The output low side FET is protected against over-current
conditions. In case of an over-current condition (e.g. LIN bus
short to VBAT), the transmitter will not be shut down. The bit
LINOC in the LIN status register (LINSR) is set.
The transmitter is automatically re-enabled once TXD is
high.
A read of the LIN status register (LINSR) with the TXD pin
is high will clear the bit TXDOM.
If the bit LINM is set in the interrupt mask register (IMR) an
Interrupt IRQ will be generated.
LIN Dominant Voltage Level Selection
Over-temperature Shutdown (LIN Interrupt)
The LIN dominant voltage level can be selected by the bit
LDVS in the LIN control register (LINCR).
The output low side FET is protected against over-
temperature conditions. In case of an over-temperature
condition, the transmitter will be shut down and the bit LINOT
in the LIN status register (LINSR) is set.
LIN Receiver Operation Only
While in Normal mode the activation of the RXONLY bit
disables the LIN TX driver. In the case of a LIN error condition
this bit is automatically set. In case a Low Power mode is
selected with this bit set, the LIN wake-up functionality is
disabled, then, in Stop mode, the RXD pin will reflect the state
of the LIN bus.
If the bit LINM is set in the interrupt mask register (IMR) an
Interrupt IRQ will be generated.
The transmitter is automatically re-enabled once the
condition is gone and TXD is high.
A read of the LIN status register (LINSR) with the TXD pin
will re-enable the transmitter.
STOP Mode And Wake-up Feature
During Stop mode operation the transmitter of the physical
layer is disabled. In case the bit LIN-PU was set in the Stop
mode sequence the internal pull-up resistor is disconnected
from VSUP and a small current source keeps the LIN pin in
the recessive state. The receiver is still active and able to
detect wake-up events on the LIN bus line.
RXD Short-circuit Detection (LIN Interrupt)
The LIN transceiver has a short-circuit detection for the
RXD output pin. In case of an short-circuit condition, either
5.0 V or ground, the bit RXSHORT in the LIN status register
(LINSR) is set and the transmitter is shutdown.
If the bit LINM is set in the interrupt mask register (IMR) an
interrupt IRQ will be generated.
A dominant level longer than tPROPWL followed by a rising
edge will generate a wake-up interrupt and will be reported in
the ISR. Also see Figure 32.
The transmitter is automatically re-enabled once the
condition is gone (transition on RXD) and TXD is high.
A read of the LIN status register (LINSR) without the RXD
pin short circuit condition will clear the bit RXSHORT.
SLEEP Mode And Wake-up Feature
During Sleep mode operation the transmitter of the
physical layer is disabled. In case the bit LIN-PU was set in
the Sleep mode sequence the internal pull-up resistor is
disconnected from VSUP and a small current source keeps
the LIN pin in recessive state. The receiver is still active to be
able to detect wake-up events on the LIN bus line.
TXD Dominant Detection (LIN Interrupt)
The LIN transceiver monitors the TXD input pin to detect
stuck in dominant (0 V) condition. In case of a stuck condition
(TXD pin 0V for more than 1 second (typ.)) the transmitter is
shut down and the bit TXDOM in the LIN status register
(LINSR) is set.
A dominant level longer than tPROPWL followed by a rising
edge will generate a system wake-up (Reset) and will be
reported in the ISR. Also see Figure 31.
33910
Analog Integrated Circuit Device Data
Freescale Semiconductor
76
FREESCALE [ Freescale ]
