atmega32c1 ATMEL Corporation, atmega32c1 Datasheet - Page 45

• Manufacturer Part Number: atmega32c1
• Description: Atmega32m1 Automotive 8-bit Avr Microcontroller With 32k/64k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

7.2.1
7647A–AVR–02/08
Power-on Reset
Figure 7-1.
Table 7-1.
Note:
A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detection level
is defined in
POR circuit can be used to trigger the start-up Reset, 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
Symbol
V
V
V
V
V
POT
PORMAX
PORMIN
CCRR
RST
CC
1. Before rising, the supply has to be between
BODLEVEL [2..0]
decreases below the detection level.
Parameter
Power-on Reset Threshold Voltage (rising)
Power-on Reset Threshold Voltage (falling)
VCC Max. start voltage to ensure internal
Power-on Reset signal
VCC Min. start voltage to ensure internal
Power-on Reset signal
VCC Rise Rate to ensure Power-on Reset
Table
RESET Pin Threshold Voltage
Reset Logic
Reset Characteristics
7-1. The POR is activated whenever V
Pull-up Resistor
Spike
Filter
CC
rise. The RESET signal is activated again, without any delay,
CKSEL[3:0]
Power-on Reset
Reset Circuit
SUT[1:0]
Brown-out
Watchdog
Oscillator
Generator
Circuit
Clock
CK
V
(1)
Register (MCUSR)
PORMIN
MCU Status
DATA BUS
ATmega32/64/M1/C1
Delay Counters
0.1 V
0.01
and V
Min
-0.1
CC
1.1
0.8
is below the detection level. The
CC
PORMAX
Typ
1.4
0.9
to ensure a Reset.
TIMEOUT
0.9V
Max
1.7
1.6
0.4
CC
Units
V/ms
V
V
V
V
V
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