The AVR32LA32 Curiosity Nano Board has a 32.768 kHz crystal
mounted. The crystal is not connected to the target device by default, as the GPIO pins
are routed to the edge connector.
Figure 7-3. 32.768 kHz Crystal Block Diagram
Note: The 32.768 kHz crystal on the AVR32LA32 Curiosity Nano is included for use and testing with the AVR32LA32 External 32.768 kHz Oscillator (XOSC32K) configured in
High-Power mode. R110 is added to limit the oscillator’s drive strength.
Table 7-3. Crystal Connections
AVR32LA32 Pin
Description
Default Connection
PA0
Crystal input, XTAL32K1
Edge connector
PA1
Crystal output, XTAL32K2
Warning: Always disconnect the
board from all power sources making any hardware modifications.
How to Connect the Crystal to the Target Device
Disconnect the two I/O lines routed to
the edge connector by cutting the two cut straps on the bottom side of the board, J107 and
J108.
Connect the two I/O lines to the crystal
by soldering a blob onto each circular solder point on the top of the board, J109 and
J110.
Figure 7-4. 32.768 kHz Crystal Overview
The 32.768 kHz crystal has a cut strap (J111), that can be used to measure the oscillator
safety factor. This is done by cutting the strap and adding a 0402 SMD resistor across it. The
AN2648 application note from Microchip provides more information
about oscillator allowance and safety factors.
DS50004120A
The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.
