SAM E70 Xplained

Overview

The SAM E70 Xplained evaluation kit is a development platform to evaluate the Atmel SAM E70 series microcontrollers.

SAM E70 Xplained

Hardware

  • ATSAME70Q21 ARM Cortex-M7 Processor
  • 12 MHz crystal oscillator
  • 32.768 kHz crystal oscillator (not populated)
  • AT24MAC402 EEPROM
  • IS42S16100E 16 Mb SDRAM
  • SD card connector
  • Ethernet port
  • Micro-AB USB device
  • Micro-AB USB debug interface supporting CMSIS-DAP, Virtual COM Port and Data Gateway Interface (DGI)
  • JTAG interface connector
  • One reset and one user pushbutton
  • One green user LED

Supported Features

The sam_e70_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
USART on-chip serial port
I2C on-chip i2c
SPI on-chip spi
ETHERNET on-chip ethernet
WATCHDOG on-chip watchdog
GPIO on-chip gpio
ADC on-chip ADC via AFEC

Other hardware features are not currently supported by Zephyr.

The default configuration can be found in the Kconfig boards/arm/sam_e70_xplained/sam_e70_xplained_defconfig.

Connections and IOs

The SAME70-XPLD User Guide has detailed information about board connections.

System Clock

The SAM E70 MCU is configured to use the 12 MHz external oscillator on the board with the on-chip PLL to generate a 300 MHz system clock.

Serial Port

The ATSAME70Q21 MCU has five UARTs and three USARTs. One of the USARTs is configured for the console and is available as a Virtual COM Port via EDBG USB chip.

Programming and Debugging

Flashing the Zephyr project onto SAM E70 MCU requires the OpenOCD tool. Support for Atmel SAM E microcontroller series was added in OpenOCD release 0.10.0, which was added in Zephyr SDK 0.9.2.

By default a factory new SAM E70 chip will boot SAM-BA boot loader located in the ROM, not the flashed image. This is determined by the value of GPNVM1 (General-Purpose NVM bit 1). The flash procedure will ensure that GPNVM1 is set to 1 changing the default behavior to boot from Flash.

If your chip has a security bit GPNVM0 set you will be unable to program flash memory or connect to it via a debug interface. The only way to clear GPNVM0 is to perform a chip erase procedure that will erase all GPNVM bits and the full contents of the SAM E70 flash memory:

  • With the board power off, set a jumper on the J200 header.
  • Turn the board power on. The jumper can be removed soon after the power is on (flash erasing procedure is started when the erase line is asserted for at least 230ms)

Flashing

  1. 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
  2. Connect the SAM E70 Xplained board to your host computer using the USB debug port. Then build and flash the Hello World application.

    # On Linux/macOS
    cd $ZEPHYR_BASE/samples/hello_world
    mkdir build && cd build
    
    # On Windows
    cd %ZEPHYR_BASE%\samples\hello_world
    mkdir build & cd build
    
    
    # Use cmake to configure a Ninja-based build system:
    cmake -GNinja -DBOARD=sam_e70_xplained ..
    
    # Now run ninja on the generated build system:
    ninja
    ninja flash
    

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

You can flash the image using an external debug adapter such as J-Link or ULINK, connected to the 20-pin JTAG header. Supply the name of the debug adapter (e.g., jlink) via an OPENOCD_INTERFACE environment variable. OpenOCD will look for the appropriate interface configuration in an interface/$(OPENOCD_INTERFACE).cfg file on its internal search path.

Debugging

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

# On Linux/macOS
cd $ZEPHYR_BASE/samples/hello_world
# If you already made a build directory (build) and ran cmake, just 'cd build' instead.
mkdir build && cd build

# On Windows
cd %ZEPHYR_BASE%\samples\hello_world
# If you already made a build directory (build) and ran cmake, just 'cd build' instead.
mkdir build & cd build

# If you already made a build directory (build) and ran cmake, just 'cd build' instead.

# Use cmake to configure a Ninja-based build system:
cmake -GNinja -DBOARD=sam_e70_xplained ..

# Now run ninja on the generated build system:
ninja debug