ATXMEGA128B1 Datasheet, PDF (82/138 Pages) ATMEL Corporation – 8/16-bit Atmel XMEGA B1 Microcontroller

Table 36-26. External clock with prescaler⁽¹⁾ for system clock
Symbol Parameter
1/t_CK Clock Frequency⁽²⁾
t_CK
Clock Period
t_CH
Clock High Time
t_CL
Clock Low Time
t_CR
Rise Time (for maximum frequency)
t_CF
Fall Time (for maximum frequency)
t_CK Change in period from one clock cycle to the next
Condition
V_CC = 1.6 - 1.8V
V_CC = 2.7 - 3.6V
V_CC = 1.6 - 1.8V
V_CC = 2.7 - 3.6V
V_CC = 1.6 - 1.8V
V_CC = 2.7 - 3.6V
V_CC = 1.6 - 1.8V
V_CC = 2.7 - 3.6V
Min
Typ
Max Units
0
90
MHz
0
142
11
7
4.5
2.4
ns
4.5
2.4
1.5
1.5
10
%
Notes:
1. System Clock Prescalers must be set so that maximum CPU clock frequency for device is not exceeded.
2. The maximum frequency vs. supply voltage is linear between 1.8V and 2.7V, and the same applies for all other parameters with supply voltage conditions
36.14.7 External 16MHz crystal oscillator and XOSC characteristics
Table 36-27. External 16MHz crystal oscillator and XOSC characteristics.
Symbol Parameter
Cycle to cycle jitter
Long term jitter
Frequency error
Duty cycle
Condition
XOSCPWR=0, FRQRANGE=0
XOSCPWR=0, FRQRANGE=1, 2, or 3
XOSCPWR=1
XOSCPWR=0, FRQRANGE=0
XOSCPWR=0, FRQRANGE=1, 2, or 3
XOSCPWR=1
XOSCPWR=0, FRQRANGE=0
XOSCPWR=0, FRQRANGE=1
XOSCPWR=0, FRQRANGE=2 or 3
XOSCPWR=1
XOSCPWR=0, FRQRANGE=0
XOSCPWR=0, FRQRANGE=1
XOSCPWR=0, FRQRANGE=2 or 3
XOSCPWR=1
Min.
Typ. Max. Units
0
0
0
ns
0
0
0
0.03
0.03
0.03
0.03
%
50
50
50
50
XMEGA B1 [DATASHEET] 82
8330C–AVR–07/2012