26.3 Clock Characteristics
26.3.1 Calibrated Internal RC Oscillator Accuracy
Table 26-1. Calibration Accuracy of Internal RC Oscillator
Frequency
VCC
Temperature
Calibration Accuracy
8.0MHz
3V
25°C
±2%
26.4 External Clock Drive Characteristics
Figure 26-1. External Clock Drive Waveforms
tCHCX
tCLCH
tCHCL
tCHCX
VIH1
VIL1
tCLCX
tCLCL
Table 26-2. External Clock Drive
VCC = 2.7 to 5.5V
VCC = 4.5 to 5.5V
Parameter
Oscillator frequency
Clock period
High time
Symbol
1/tCLCL
tCLCL
Min.
0
Max.
Min.
0
Max.
Unit
MHz
ns
8
16
125
50
62.5
25
tCHCX
tCLCX
tCLCH
tCHCL
ns
Low time
50
25
ns
Rise time
1.6
1.6
0.5
0.5
µs
Fall time
µs
Change in period from one clock cycle to the
next
tCLCL
2
2
%
276
ATmega16/32/64/M1/C1 [DATASHEET]
7647O–AVR–01/15
MICROCHIP [ MICROCHIP ]
