MC33910BAC / MC34910BAC
FUNCTIONAL DEVICE OPERATIONS
OPERATIONAL MODES
Table 35. Operating Modes Overview
Function
VDD
Reset Mode Normal Request Mode Normal Mode
Stop Mode
Sleep Mode
full
full
SPI(118)
full
SPI
stop
-
HVDD
HSx
-
-
-
-
SPI/PWM(119)
SPI
SPI/PWM
SPI
Note(120)
-
Note(121)
Analog Mux
L1
-
-
-
Input
Input
Wake-up
Wake-up
LIN
-
Rx-Only
full/Rx-Only Rx-Only/Wake-up
Wake-up
Watchdog
VSENSE
-
150 ms (typ.) timeout
On
On(62)/Off
On
-
-
-
On
VDD
Notes
118. Operation can be enabled/controlled by the SPI.
119. Operation can be controlled by the PWMIN input.
120. HSx switches can be configured for cyclic sense operation in Stop mode.
121. HSx switches can be configured for cyclic sense operation in Sleep mode.
122. Windowing operation when enabled by an external resistor.
Over-temperature Prewarning
INTERRUPTS
Interrupts are used to signal a microcontroller that a
peripheral needs to be serviced. The interrupts which can be
generated change according to the Operating mode. While in
Normal and Normal Request modes the 33910 signals
through interrupts special conditions which may require a
MCU software action. Interrupts are not generated until all
pending wake-up sources are read in the interrupt source
register (ISR).
Signals when the 33910 temperature has reached the pre-
shutdown warning threshold. It is used to warn the MCU that
an over-temperature shutdown in the main 5.0 V regulator is
imminent.
LIN Over-current Shutdown / Over-temperature
Shutdown / TXD Stuck At Dominant / RXD Short-circuit
These signal faulty conditions in the LIN interface (except
the LIN over-current) that had led to disable the LIN driver. In
order to restart operation, the fault must be removed and
must be acknowledged by reading the SPI.
While in Stop mode, interrupts are used to signal wake-up
events. Sleep mode does not use interrupts, wake-up is
performed by powering-up the MCU. In Normal and Normal
Request mode the wake-up source can be read by SPI.
The LINOC bit functionality in the LIN status register
(LINSR) is to indicate that an LIN over-current occurred and
the driver stays enabled.
The interrupts are signaled to the MCU by a low logic level
of the IRQ pin, which will remain low until the interrupt is
acknowledged by a SPI read. The IRQ pin will then be driven
high.
High Side Over-temperature Shutdown
Interrupts are only asserted while in Normal-, Normal
Request and Stop mode. Interrupts are not generated while
the RST pin is low.
Signals a shutdown of the high side outputs.
RESET
Following is a list of the interrupt sources in Normal and
Normal Request modes, some of those can be masked by
writing to the SPI-interrupt mask register (IMR).
To reset an MCU, the 33910 drives the RST pin low for the
time the reset condition lasts.
After the reset source has been removed the state
machine will drive the RST output low for at least 1.0 ms
typical value before driving it high.
Low Voltage Interrupt
Signals when the supply line (VS1) voltage drops below
the VSUV threshold (VSUV).
In the 33910 four main reset sources exist:
5V Regulator Low-Voltage-Reset (VRSTTH
)
High Voltage Interrupt
The 5V regulator output VDD is continuously monitored
against brown outs. If the supply monitor detects that the
voltage at the VDD pin has dropped below the reset threshold
VRSTTH the 33910 will issue a reset. In case of over-
temperature, the voltage regulator will be disabled and the
Signals when the supply line (VS1) voltage increases
above the VSOV threshold (VSOV).
33910
Analog Integrated Circuit Device Data
Freescale Semiconductor
71
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