eCosCentric will shortly be releasing the TAP-HAT. If you would like to be kept informed of the latest news and updates then please register your interest.

The TAP-HAT is a low-cost hardware debugger for the Raspberry Pi^®. Its flexible multi-modal design supports USB-connected hardware debugging of a Pi board, connection of external hardware debuggers to a Pi, or use of the Pi as a network attached hardware debugger.

Key Features

• Low-cost multi-purpose JTAG debugger for Raspberry Pi boards
• Optional add-on modules enable USB-connected debugging of Pi and/or UART debug output
• Straightforward attachment of external JTAG debuggers to the Pi
• Use with OpenOCD server running native on Pi to create a low-cost networked hardware debugger
• Stackable reverse-HAT design allows concurrent connection of standard peripheral HATs
• Redboot bootloader supports configuration of Pi JTAG pin map and high-speed serial debugging
• Supports JTAG initiated system reset of Pi
• Can be used for bare-metal applications, eCosPro RTOS applications, and other OSes such as Linux

The TAP-HAT enables the straightforward fool-proof connection of external JTAG debuggers. This includes popular hardware debuggers such as the Lauterbach TRACE32, Ronetix PEEDI, SEGGER J-Link and many others. Simply connect the hardware debugger's standard 20-way ARM JTAG cable to the TAP-HAT's JTAG socket and boot the Pi. Remote reset of the Pi is supported by connection of included flying probe to the Pi reset pin.

An FTDI Mini-Module can be optionally installed in the board to provide both a USB-based JTAG debug capability and debug UART output to a connected PC. Supported modules include the FTDI FT2232H and FT2232H-56Q. The open source OpenOCD server is used to provide GNU GDB connectivity.

Alternatively the TAP-HAT's standard FTDI 6-pin header enables straightforward installation of basic UART to USB converters such as the low-cost FTDI LC234X. This can be used to provide terminal access to the Pi, capture debug output, or in conjunction with the RedBoot bootloader's debug agent, direct high-speed serial debugging of the Pi with GDB.

The OpenOCD server can be run natively on a Pi equipped with a TAP-HAT to create a network connected hardware debugger. This can be used to debug another TAP-HAT connected Pi, or other embedded targets that provide external 3.3v JTAG/SWD connections. Debugging of specific architectures, processors and boards is dependent on available OpenOCD support.

Pi JTAG connectivity is disabled by default. The included RedBoot SD card bootloader enables JTAG functionality and configures the CPUs alternate pin mappings to match the TAP-HAT board's jumper settings. This provides flexibility and maximises compatibility with Pi peripherals.

Included accessory pack contains Pi reset header, probe clip and flying lead for external reset connection, 20-way ARM JTAG cable for connection to other boards, and board stand-off legs.

eCosCentric will be releasing the TAP-HAT shortly. If you would like to be kept informed of the latest news and updates then please register your interest.