platform-teensy-gcc10/boards/teensy30.json

{
  "build": {
    "arduino": {
      "ldscript": "mk20dx128.ld"
    },
    "core": "teensy3",
    "cpu": "cortex-m4",
    "extra_flags": "-D__MK20DX128__ -DARDUINO_TEENSY30",
    "f_cpu": "48000000L",
    "mcu": "mk20dx128"
  },
  "frameworks": [
    "arduino"
  ],
  "name": "Teensy 3.0",
  "upload": {
    "maximum_ram_size": 16384,
    "maximum_size": 131072,
    "protocol": "teensy-gui",
    "protocols": [
      "teensy-cli",
      "teensy-gui"
    ]
  },
  "url": "https://www.pjrc.com/store/teensy3.html",
  "vendor": "Teensy"
}