NXP Semiconductors MPC5777M - Reset Pad (PORST, ESR0) Electrical Characteristics

MPC5777M Microcontroller Data Sheet, Rev. 6
Electrical characteristics
NXP Semiconductors44
3.8 Reset pad (PORST, ESR0) electrical characteristics
The device implements a dedicated bidirectional reset pin (PORST).
NOTE
PORST pin does not require active control. It is possible to implement an external pull-up
to ensure correct reset exit sequence. Recommended value is 4.7 k.
Figure 10. Start-up reset requirements
Figure 11 describes device behavior depending on supply signal on PORST
:
1. PORST
low pulse amplitude is too low—it is filtered by input buffer hysteresis. Device remains in current state.
2. PORST
low pulse duration is too short—it is filtered by a low pass filter. Device remains in current state.
3. PORST
low pulse generates a reset:
a) PORST
low but initially filtered during at least W
FRST
. Device remains initially in current state.
b) PORST
potentially filtered until W
NFRST
. Device state is unknown: it may either be reset or remains in current
state depending on other factors (temperature, voltage, device).
c) PORST
asserted for longer than W
NFRST
. Device is under reset.
2
During power up operation, the minimum required voltage to come out of reset state is determined by the V
PORUP_HV
monitor, which is defined in the voltage monitor electrical characterstics table. Note that the V
PORUP_HV
monitor is
connected to the V
DD_HV_IO_MAIN0
physical I/O segment.
3
Stated maximum values represent peak consumption that lasts only a few ns during I/O transition. When possible
(timed output) it is recommended to delay transition between pads by few cycles to reduce noise and consumption.
4
For I
DYN_EBI_GPIO
dynamic current for EBI GPIO mode use the I
DYN_M
values.
V
IL
V
DD
V
DDMIN
PORST
V
IH
device start-up phase
V
DD_POR
PORST undriven.
Device reset by
internal power-on
reset.
PORST driven low by
internal power-on reset.
Device reset forced by
external circuitry.