Datasheet

331
7674F–AVR–09/09
ATmega164P/324P/644P
26.3 Clock Characteristics
26.3.1 External Clock Drive Waveforms
Figure 26-2. External Clock Drive Waveforms
26.3.2 External Clock Drive
Note: 1. Values indicated represent typical data from design simulation.
Table 26-2. Calibration Accuracy of Internal RC Oscillator
Frequency V
CC
Temperature Calibration Accuracy
Factory
Calibration
8.0 MHz 3V 25°C±2%
2.7V - 5.5V -40°C - 125°C ±14%
V
IL1
V
IH1
Table 26-3. External Clock Drive
(1)
Symbol Parameter
V
CC
=2.7-5.5V V
CC
=4.5-5.5V
UnitsMin. Max. Min. Max.
1/t
CLCL
Oscillator
Frequency
08016MHz
t
CLCL
Clock Period 125 62.5 ns
t
CHCX
High Time 50 25 ns
t
CLCX
Low Time 50 25 ns
t
CLCH
Rise Time 1.6 0.5 µs
t
CHCL
Fall Time 1.6 0.5 µs
Δt
CLCL
Change in period
from one clock
cycle to the next
22%