Figure 23. Reset Logic
DATA BUS
MCU Status
Register (MCUSR)
Power-on Reset
Circuit
Brown-out
Reset Circuit
BODLEVEL [2..0]
Pull-up Resistor
Spike
Filter
JTAG Reset
Register
Watchdog
Oscillator
Delay Counters
Clock
Generator
CK
TIMEOUT
CKSEL[3:0]
SUT[1:0]
Table 19. Reset Characteristics
Symbol Parameter
Condition
Min.
Typ.
1.4
Max. Units
Power-on Reset Threshold Voltage (rising)
Power-on Reset Threshold Voltage (falling)(1)
2.3
2.3
V
V
VPOT
1.3
VRST
tRST
RESET Pin Threshold Voltage
0.2 VCC
0.85 VCC
V
Minimum pulse width on RESET Pin
Vcc = 5 V, temperature = 25 °C
400
ns
Notes: 1. The Power-on Reset will not work unless the supply voltage has been below VPOT
(falling)
48
AT90CAN128
4250E–CAN–12/04
ATMEL [ ATMEL ]
