ATMEGA32_14 Datasheet, PDF (37/346 Pages) ATMEL Corporation – High Endurance Non-volatile Memory segments

2503Q–AVR–02/11
ATmega32(L)
Figure 15. Reset Logic
DATA BUS
MCU Control and Status
Register (MCUCSR)
Power-on
Reset Circuit
BODEN
BODLEVEL
Pull-up Resistor
SPIKE
FILTER
Brown-out
Reset Circuit
Reset Circuit
JTAG Reset
Register
Watchdog
Timer
Watchdog
Oscillator
Clock
CK
Generator
Delay Counters
TIMEOUT
CKSEL[3:0]
SUT[1:0]
Table 15. Reset Characteristics
Symbol Parameter
Condition
Min Typ Max Units
V_POT
Power-on Reset
Threshold Voltage (rising)
Power-on Reset
Threshold Voltage
(falling)⁽¹⁾
1.4
2.3
V
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
Minimum low voltage
BODLEVEL = 1
2
µs
t_BOD
period for Brown-out
Detection
BODLEVEL = 0
2
µs
V_HYST
Brown-out Detector
hysteresis
50
mV
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.
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