Rainbow Electronics ATmega64M1 - Manual (Page 312)

312
8209A–AVR–08/09
ATmega16M1/32M1/64M1
29.4 Clock Characteristics
29.4.1 Calibrated Internal RC Oscillator Accuracy
29.5 External Clock Drive Characteristics
Figure 29-2. External Clock Drive Waveforms
Table 29-1. Calibration Accuracy of Internal RC Oscillator
Frequency V
CC
Temperature Calibration Accuracy
Factory
Calibration
8.0 MHz 3V 25
°
C ±1%
User
Calibration
7.3 - 8.1 MHz 2.7V - 5.5V -40
°
C to +85
°
C ±10%
Table 1. External Clock Drive
Symbol Parameter
V
CC
= 2.7 - 5.5V V
CC
= 4.5 - 5.5V
Units Min. Max. Min. Max.
1/t
CLCL
Oscillator Frequency 0 8 0 16 MHz
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
μ
s
t
CHCL
Fall Time 1.6 0.5
μ
s
Δ
t
CLCL
Change in period from one clock cycle
to the next
2 2 %
V
IL1
V
IH1