Datasheet

37
2503Q–AVR–02/11
ATmega32(L)
Figure 15. Reset Logic
Notes: 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 ATmega32L and BODLEVEL = 0 for ATmega32. BODLEVEL = 1 is not
applicable for ATmega32.
Table 15. Reset Characteristics
Symbol Parameter Condition Min Typ Max Units
V
POT
Power-on Reset
Threshold Voltage (rising)
1.4 2.3 V
Power-on Reset
Threshold Voltage
(falling)
(1)
1.3 2.3 V
V
RST
RESET Pin Threshold
Voltage
0.2V
CC
0.9V
CC
V
t
RST
Minimum pulse width on
RESET
Pin
1.5 µs
V
BOT
Brown-out Reset
Threshold Voltage
(2)
BODLEVEL = 1 2.5 2.7 2.9
V
BODLEVEL = 0 3.6 4.0 4.2
t
BOD
Minimum low voltage
period for Brown-out
Detection
BODLEVEL = 1 2 µs
BODLEVEL = 0 2 µs
V
HYST
Brown-out Detector
hysteresis
50 mV
MCU Control and Status
Register (MCUCSR)
BODEN
BODLEVEL
Delay Counters
CKSEL[3:0]
CK
TIMEOUT
WDRF
BORF
EXTRF
PORF
DATA B U S
Clock
Generator
SPIKE
FILTER
Pull-up Resistor
JTRF
JTAG Reset
Register
Watchdog
Oscillator
SUT[1:0]
Watchdog
Timer
Reset Circuit
Brown-out
Reset Circuit
Power-on
Reset Circuit
INTERNAL RESET
COUNTER RESET