SAM4S Xplained


The SAM4S Xplained evaluation kit is a development platform to evaluate the Atmel SAM4S series microcontrollers.

SAM4S Xplained


  • ATSAM4S16C ARM Cortex-M4 Processor
  • 12 MHz crystal oscillator
  • internal 32.768 kHz crystal oscillator
  • IS66WV51216DALL 8 Mb SRAM
  • Micro-AB USB device
  • Micro-AB USB debug interface supporting SEGGER OB and Virtual COM Port and Data
  • One reset and one user pushbutton
  • 2 yellow user LEDs
  • IC pads for external flash chip

Supported Features

The sam4s_xplained board configuration supports the following hardware features:

Interface Controller Driver/Component
NVIC on-chip nested vector interrupt controller
SYSTICK on-chip systick
UART on-chip serial port
I2C on-chip i2c
GPIO on-chip gpio
Watchdog on-chip watchdog

Other hardware features are not currently supported by Zephyr.

The default configuration can be found in the Kconfig boards/arm/sam4s_xplained/sam4s_xplained_defconfig.

Connections and IOs

The SAM4S Xplained Online User Guide [1] has detailed information about board connections. Download the SAM4S Xplained Schematic [3] for more detail.

System Clock

The SAM4S MCU is configured to use the 12 MHz internal oscillator on the board with the on-chip PLL to generate an 84 MHz system clock.

Serial Port

The ATSAM4S16C MCU has 2 UARTs and 2 USARTs. One of the UARTs (UART0) is connected to the Segger J-Link OB chip (the AT91SAM3U4 is programmed to be Segger J-Link OB). Segger J-Link OB brings the UART out as a virtual COM port. The section flashing uses the UART from the Segger USB debug connection.

Programming and Debugging

The SAM4S Xplained board comes with Segger J-Link OB. This provides a debug interface to the SAM4S16C chip. You can use Ozone or JLink to communicate with the SAM4S16C.


  1. Download JLink from the Segger JLink Downloads Page [2]. Go to the section “J-Link Software and Documentation Pack” and install the “J-Link Software and Documentation pack for Linux”. The application JLinkExe needs to be accessible from your path.

  2. Run your favorite terminal program to listen for output. Under Linux the terminal should be /dev/ttyACM0. For example:

    $ minicom -D /dev/ttyACM0 -o

    The -o option tells minicom not to send the modem initialization string. Connection should be configured as follows:

    • Speed: 115200
    • Data: 8 bits
    • Parity: None
    • Stop bits: 1
  3. Connect the SAM4S Xplained board to your host computer using the USB debug port. Then build and flash the Hello World application.

    # From the root of the zephyr repository
    west build -b sam4s_xplained samples/hello_world
    west flash

    You should see “Hello World! arm” in your terminal.


You can debug an application in the usual way. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b sam4s_xplained samples/hello_world
west debug