CC2430 Datasheet, PDF (144/234 Pages) Texas Instruments – A True System-on-Chip solution for 2.4 GHz IEEE 802.15.4 / ZigBee-TM

CC2430
13.11 Power On Reset and Brown Out
Detector
The CC2430 includes a Power On Reset
(POR) and Brown Out Detector (BOD) in
order to protect the memory contents
during supply voltage variations and
provide correct initialization during power-
on.
When power is initially applied to the
CC2430 the Power On Reset (POR) and
Brown Out Detector (BOD) will hold the
device in reset state until the supply
voltage reaches above the Power On
Reset and Brown Out voltages as defined
in Table 4 on page 12.
Figure 32 shows the POR/BOD operation
with the 1.8V (typical) regulated supply
voltage together with the active low reset
signals BOD_RESET and POR_RESET
shown in the bottom of the figure.
The cause of the last reset can read from
the register bits SLEEP.RST.
VOLT
1.8V REGULATED
UNREGULATED
BOD RESET ASSERT
POR RESET DEASSERT RISING VDD
POR RESET ASSERT FALLING VDD
0
POR OUTPUT _X
X
BOD RESET
X
X
POR RESET _X
X
Figure 32 : Power On Reset and Brown Out Detector Operation
CC2430 PRELIMINARY Data Sheet (rev. 1.03) SWRS036A
Page 144 of 232