Rainbow Electronics ATmega32L - Manual (Page 35)

35
ATmega32(L)
2503C–AVR–10/02
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 guarantees 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
0.2 V
CC
0.85V
CC
V
t
RST
Minimum pulse width on
RESET Pin
50 ns
V
BOT
Brown-out Reset
Threshold Voltage
(2)
BODLEVEL = 1 2.5 2.7 3.2
V
BODLEVEL = 0 3.7 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 BUS
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