Data Sheet

1088
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
A.8 Oscillators Characteristics
A.8.1 Crystal Oscillator (XOSC) Characteristics
Digital Clock Characteristics
The following table describes the characteristics for the oscillator when a digital clock is applied on XIN.
Table A-35. Digital Clock Characteristics
Crystal Oscillator Characteristics
The following table describes the characteristics for the oscillator when a crystal is connected between XIN and XOUT as
shown in Figure A-4. The user must choose a crystal oscillator where the crystal load capacitance
C
L
is within the range
given in the table. The exact value of C
L
can be found in the crystal datasheet. The capacitance of the external capacitors
(C
LEXT
) can then be computed as follows:
where C
STRAY
is the capacitance of the pins and PCB, C
SHUNT
is the shunt capacitance of the crystal.
Table A-34. NVM Characteristics
Symbol Parameter Conditions Min. Typ. Max. Units
t
FPP
Page programming time - - - 2.5 ms
t
FRE
Row erase time I - - - 6 ms
t
FCE
DSU chip erase time
(CHIP_ERASE)
- - - 240 ms
Symbol Parameter Conditions Min. Typ. Max. Units
f
CPXIN
XIN clock frequency
I
- - 32 MHz
C
LEXT
2C
L
C
STRAY
C
SHUNT
––()=