ATmega16(L)
Figure 15.
Reset Logic
DATA BUS
MCU Control
and
Status
Register (MCUCSR)
PORF
BORF
EXTRF
WDRF
JTRF
Power-on
Reset Circuit
Pull-up Resistor
SPIKE
FILTER
Reset Circuit
COUNTER RESET
JTAG Reset
Register
Watchdog
Timer
Watchdog
Oscillator
Clock
Generator
CK
Delay Counters
TIMEOUT
CKSEL[3:0]
SUT[1:0]
Table 15.
Reset Characteristics
Symbol
Parameter
Power-on Reset
Threshold Voltage (rising)
V
POT
Power-on Reset
Threshold Voltage
(falling)
RESET Pin Threshold
Voltage
Minimum pulse width on
RESET Pin
Brown-out Reset
Threshold Voltage
Minimum low voltage
period for Brown-out
Detection
BODLEVEL = 1
BODLEVEL = 0
BODLEVEL = 1
BODLEVEL = 0
2.5
3.6
2.7
4.0
2
2
0.1 V
CC
Condition
Min
Typ
1.4
Max
2.3
Units
V
1.3
2.3
INTERNAL RESET
BODEN
BODLEVEL
Brown-out
Reset Circuit
V
V
RST
t
RST
V
BOT
0.9V
CC
1.5
3.2
V
µs
V
4.5
µs
µs
t
BOD
V
HYST
Notes:
Brown-out Detector
50
mV
hysteresis
1. The Power-on Reset will not work unless the supply voltage has been below V
POT
(falling).
2. V
BOT
may be below nominal minimum operating voltage for some devices. For devices where
this is the case, the device is tested down to V
CC
= V
BOT
during the production test. This guar-
antees that a Brown-out Reset will occur before V
CC
drops to a voltage where correct
operation of the microcontroller is no longer guaranteed. The test is performed using
BODLEVEL = 1 for ATmega16L and BODLEVEL = 0 for ATmega16. BODLEVEL = 1 is not
applicable for ATmega16.
38
2466S–AVR–05/09
ATMEL [ ATMEL CORPORATION ]
