Microchip Technology EV76S68A, User Manual

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Tip: There is no pull-up resistor connected to the generic user switch. Remember to enable the internal
pull-up in the SAME51J20A to use the switch.
Table 4-2. Mechanical Switch
SAME51J20A Function Shared Functionality
PA15 User Switch SW0 None
4.2.3 Crystal
The SAME51J20A Curiosity Nano board has a 32.768 kHz crystal.
By default, the crystal is populated and connected to the SAME51J20A and these pins are not usable as a GPIO. To
use the crystal, no hardware modifications are required.
Table 4-3. Crystal Connections
SAME51J20A pin Function Shared Functionality
PA00 XIN32 None
PA01 XOUT32 None
4.3 On-Board Debugger Implementation
The SAME51J20A Curiosity Nano features an on-board debugger that can be used to program and debug the
SAME51J20A using a Serial Wire Debug (SWD). The on-board debugger also includes a virtual COM port interface
over UART and DGI GPIO. MPLAB X IDE can be used as a front-end for the on-board debugger for programming
and debugging. A data visualizer can be used as a front-end for the CDC and DGI GPIO.
4.3.1 On-Board Debugger Connections
The following table shows the connections between the target and the debugger section. All connections between the
target and the debugger are tri-stated as long as the debugger is not actively using the interface, therefore there is
little contamination of the signals and the pins can be configured to the application requirements. For additional
information on how to use the capabilities of the on-board debugger, see
Curiosity Nano .
Table 4-4. On-Board Debugger Connections
SAME51J20A pin Debugger pin Function Shared Functionality
PB17 CDC TX UART TX (SAME51J20A RX line) Edge Connector
PB16 CDC RX UART RX (SAME51J20A TX line Edge Connector
PA31 DBG0 SWDATA Edge Connector
PA30 DBG1 SWCLK Edge Connector
PB30 DBG2 SWO Edge Connector
nRESET DBG3 nRESET Edge Connector
VCC_TARGET VCC_LEVEL 1.8-3.6v supply voltage Edge Connector
GND GND Common ground Edge Connector
4.3.2 Extra Ports
This implementation has two pins that are not brought out to the edge connector, the access to these are provided as
surface mount test points.
EV76S68A
Hardware
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2020 Microchip Technology Inc.
User Guide
DS70005432A-page 13