ATA5771_09 ATMEL [ATMEL Corporation], ATA5771_09 Datasheet - Page 96

• Manufacturer Part Number: ATA5771_09
• Description: Microcontroller with UHF ASK/FSK Transmitter
• Manufacturer: ATMEL [ATMEL Corporation]

9.0.5
9.0.6
7701C–AVR–12/08
Brown-out Detection
Watchdog Reset
ATtiny24/44/84 has an On-chip Brown-out Detection (BOD) circuit for monitoring the V
during operation by comparing it to a fixed trigger level. The trigger level for the BOD can be
selected by the BODLEVEL Fuses. The trigger level has a hysteresis to ensure spike free
Brown-out Detection. The hysteresis on the detection level should be interpreted as V
V
When the BOD is enabled, and V
9-5 on page
trigger level (V
out period t
The BOD circuit will only detect a drop in V
ger than t
Figure 9-5.
When the Watchdog times out, it will generate a short reset pulse of one CK cycle duration. On
the falling edge of this pulse, the delay timer starts counting the Time-out period t
”Watchdog Timer” on page 44
Figure 9-6.
BOT
+ V
HYST
BOD
CC
TOUT
43), the Brown-out Reset is immediately activated. When V
/2 and V
given in
Brown-out Reset During Operation
Watchdog Reset During Operation
BOT+
INTERNAL
TIME-OUT
has expired.
RESET
RESET
in
V
CC
BOT-
”System and Reset Characterizations” on page
Figure 9-5 on page
= V
BOT
for details on operation of the Watchdog Timer.
- V
CC
HYST
decreases to a value below the trigger level (V
V
CK
BOT-
/2.
43), the delay counter starts the MCU after the Time-
CC
if the voltage stays below the trigger level for lon-
V
t
TOUT
BOT+
ATtiny24/44/84
182.
CC
increases above the
BOT-
TOUT
in
CC
BOT+
Figure
. See
level
43
=