�
tot
=
�
�1
+ �
�1
+ �
EL1
�
�2
+ �
�2
+ �
EL2
�
�1
+ �
�1
+ �
EL1
+ �
�2
+ �
�2
+ �
EL2
where C
tot
is the total load capacitance seen by the crystal. This value should be equal to the load
capacitance value found in the crystal manufacturer datasheet.
The parasitic capacitance C
ELn
can in most applications be disregarded as these are usually very small. If
accounted for, these values are dependent on the PCB material and PCB layout.
For some crystal the internal capacitive load provided by the device itself can be enough. To calculate the
total load capacitance in this case. C
ELn
and C
Pn
are both zero, C
L1
= C
L2
= C
L
, and the equation reduces
to the following:
�
tot
=
�
�
2
See the related links for equivalent internal pin capacitance values.
Related Links
External 32KHz Crystal Oscillator (XOSC32K) Characteristics
on page 1171
48.7. Programming and Debug Ports
For programming and/or debugging the SAM L22, the device should be connected using the Serial Wire
Debug, SWD, interface. Currently the SWD interface is supported by several Atmel and third party
programmers and debuggers, like the Atmel-ICE, SAM-ICE, JTAGICE3 or SAM L22 Xplained Pro (SAM
L22 evaluation kit) Embedded Debugger.
Refer to the Atmel-ICE, SAM-ICE, JTAGICE3 or SAM L22 Xplained Pro user guides for details on
debugging and programming connections and options. For connecting to any other programming or
debugging tool, refer to that specific programmer or debugger’s user guide.
The SAM L22 Xplained Pro evaluation board supports programming and debugging through the onboard
embedded debugger so no external programmer or debugger is needed.
Note:
A pull-up resistor on the SWCLK pin is critical for reliable operation. Refer to related link for more
information.
Figure 48-12. SWCLK Circuit Connections
SWCLK
1kΩ
V
DD
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
1201