MC33989PEG Freescale Semiconductor, MC33989PEG Datasheet - Page 43

• Manufacturer Part Number: MC33989PEG
• Description: SBC-HS
• Manufacturer: Freescale Semiconductor

Failure on VDD1, Watchdog, Reset, INT Pins
of VDD1.
Power Up and SBC Entering Normal Operation
if no watchdog is written (no TIM1 register write) a reset occurs, and the SBC returns to normal request mode.During this
sequence WD is active (low level).
pin is high. If the watchdog is not refreshed, the SBC generates a reset and returns to Normal request mode.
Power Up and V
for instance by an over-current or short-circuit (ex short to 4.0 V), and if a low power mode previously selected was stop mode,
the SBC enters reset mode (reset pin is active). The pin WD stays high, but the high level (V
interrupt pin goes low.
Analog Integrated Circuit Device Data
Freescale Semiconductor
SPI (CS)
VDD1
WD
RST
INT
The paragraphs below describe the behavior of the device and of the INT, RST, and WD pins at power up and under failure
After a power-up the SBC enters in Normal request mode (CAN interface is in TX/RX mode): V
Once watchdog is written the SBC goes to normal mode: V
The first part of the following figure is identical to the above. If V
When the V
SBC in
RESET
mode
DD1
DD1
overload condition is removed, the SBC restarts in Normal request mode.
Going Low with Stop Mode as Default Low Power Mode Selected
Reset every 350 ms
SBC in Normal request
mode
350 ms
Figure 23. Power Up and SBC Entering Normal Operation
Write Watchdog each X ms
SBC in Normal
mode
DD1
is still on and V2 turns on, WD is no longer active and the reset
DD1
is pulled below the V
SBC in Normal
request mode
SUPPLEMENTAL APPLICATION NOTES
DD1
OH
No Watchdog is written
) follows the V
DD1
under-voltage reset (typ 4.6 V)
is on, V2 is off. After 350 ms
TYPICAL APPLICATIONS
SBC in Normal
mode
DD1
level. The
33989
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