mc33742 Freescale Semiconductor, Inc, mc33742 Datasheet - Page 54

• Manufacturer Part Number: mc33742
• Description: Mc33742 System Basis Chip Sbc With Enhanced High-speed Can Transceiver
• Manufacturer: Freescale Semiconductor, Inc

POWER UP AND VDD GOING LOW WITH STOP MODE AS DEFAULT LOW POWER MODE IS SELECTED
overcurrent or short circuit (for instance, short to 4.0 V), and if a low power mode previously selected was Stop mode, the 33742
enters Reset mode (
LOW.
54
33742
TYPICAL APPLICATIONS
The first part of Figure 34 is identical to Figure 33. If VDD is pulled below VDD undervoltage reset (typ 4.6 V), say by an
When the VDD overload condition is removed, the 33742 restarts in Normal Request mode.
VDD
VDD
SPI
SPI
RST
RST
INT
INT
WD
WD
(CS)
(CS)
VDD
VDD
SPI
SPI
RST
RST
INT
INT
WD
WD
(CS)
(CS)
SBC in
SBC in
RESET
RESET
mode
mode
RST
SBC in
SBC in
RESET
RESET
mode
mode
350 ms
350 ms
pin is active). The
SBC in Normal request
SBC in Normal request
& reset modes
& reset modes
Reset each 350 ms
Reset each 350 ms
SBC in Normal request
SBC in Normal request
& reset modes
& reset modes
Reset each 350 ms
Reset each 350 ms
Figure 33. Power up sequence, No W/D write at first
WDOG
Figure 34. Undervoltage on VDD
pin stays HIGH, but the high level (Voh) follows V1 level. The
SBC in Normal
SBC in Normal
mode
mode
Watchdog refresh
Watchdog refresh
SBC in Normal
SBC in Normal
mode
mode
Watchdog refresh
Watchdog refresh
SBC in Normal
SBC in Normal
request & reset
request & reset
modes
modes
SBC in Reset
SBC in Reset
mode
mode
Under voltage at VDD
Under voltage at VDD
(VDD < V
(VDD < V
Analog Integrated Circuit Device Data
Missing watchdog refresh
Missing watchdog refresh
RSTTH
RSTTH
350 ms
350 ms
)
)
Freescale Semiconductor
Watchdog
Watchdog
refresh
refresh
INT
pin goes