Datasheet

135
XMEGA D4 [DATASHEET]
8135P–AVR–01/2014
32.4.13.6 External clock characteristics
Figure 32-24.External clock drive waveform
Table 32-109. External clock used as system clock without prescaling.
Note: 1. System Clock Prescalers must be set so that maximum CPU clock frequency for device is not exceeded.
t
CH
t
CL
t
CK
t
CH
V
IL1
V
IH1
t
CR
t
CF
Symbol Parameter Condition Min. Typ. Max. Units
1/t
CK
Clock frequency
(1)
V
CC
= 1.6 - 1.8V 0 12
MHz
V
CC
= 2.7 - 3.6V 0 32
t
CK
Clock period
V
CC
= 1.6 - 1.8V 83.3
ns
V
CC
= 2.7 - 3.6V 31.5
t
CH
Clock high time
V
CC
= 1.6 - 1.8V 30.0
V
CC
= 2.7 - 3.6V 12.5
t
CL
Clock low time
V
CC
= 1.6 - 1.8V 30.0
V
CC
= 2.7 - 3.6V 12.5
t
CR
Rise time (for maximum frequency)
V
CC
= 1.6 - 1.8V 10
V
CC
= 2.7 - 3.6V 3
t
CF
Fall time (for maximum frequency)
V
CC
= 1.6 - 1.8V 10
V
CC
= 2.7 - 3.6V 3
t
CK
Change in period from one clock cycle to the next 10 %