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+## GDB Server
+
+```sh
+./JLinkGDBServerCLExe -select USB=0 -device ATSAMD21E17D -endian little -if SWD -speed 4000 -noir -LocalhostOnly -nologtofile -port 2331 -SWOPort 2332 -TelnetPort 2333
+```
+
+## RTT Telnet
+
+```sh
+telnet localhost 19021
+```