ATA5771_09 ATMEL [ATMEL Corporation], ATA5771_09 Datasheet - Page 93

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

9.0.3
40
ATtiny24/44/84
Power-on Reset
Figure 9-1.
A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detection level
is defined in
ever V
as well as to detect a failure in supply voltage.
A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. Reaching the
Power-on Reset threshold voltage invokes the delay counter, which determines how long the
device is kept in RESET after V
when V
Figure 9-2.
INTERNAL
V
TIME-OUT
BODLEVEL [1..0]
CC
CC
CC
RESET
RESET
is below the detection level. The POR circuit can be used to trigger the Start-up Reset,
decreases below the detection level.
V
”System and Reset Characterizations” on page
CCRR
Reset Logic
MCU Start-up, RESET Tied to V
Pull-up Resistor
FILTER
SPIKE
V
V
V
RST
PORMA X
PORMIN
CC
t
TOUT
CKSEL[1:0]
rise. The RESET signal is activated again, without any delay,
Power-on Reset
Reset Circuit
SUT[1:0]
Brown-out
Watchdog
Oscillator
Generator
Circuit
Clock
CK
CC
Register (MCUSR)
MCU Status
DATA BUS
Delay Counters
182. The POR is activated when-
TIMEOUT
7701C–AVR–12/08