Texas Instruments MSP430x1xx - Power-On Reset (POR)

System Reset and Initialization
2-3
System Resets, Interrupts, and Operating Modes
2.1.1 Power-On Reset (POR)
When the V
CC
rise time is slow, the POR detector holds the POR signal active
until V
CC
has risen above the V
POR
level, as shown in Figure 2−2. When the
V
CC
supply provides a fast rise time the POR delay, t
(POR_DELAY)
, provides
active time on the POR signal to allow the MSP430 to initialize.
If power to the MSP430 is cycled, the supply voltage V
CC
must fall below V
min
to ensure that another POR signal occurs when V
CC
is powered up again. If
V
CC
does not fall below V
min
during a cycle or a glitch, a POR is not generated
and power-up conditions do not set correctly. See device-specific datasheet
for parameters.
Figure 2−2. POR Timing
V
No POR
PORPOR
V
POR
V
t
(POR_DELAY)
t
(POR_DELAY)
Set Signal for
POR circuitry
min
V
CC(min)
V
CC