3.15.1. Debug and Config port support

The PB-A8 supports debugging and configuration using embedded and external hardware. The debugging interface is controlled by JTAG, the configuration interface is controlled by either JTAG or USB.

JTAG hardware

The RealView Debugger, for example, uses an external RealView ICE interface box to connect to the JTAG connector on the rear panel. See JTAG for pinout details.


The JTAG connector also supports Single Wire JTAG via the SWJ-DP port of the CoreSight DAP in the Debug FPGA. See JTAG for the SWJ pinout and Debug FPGA for interconnect details.

USB config port

The USB config port is implemented by a PLD on the PB-A8. An application, Progcards USB can control the JTAG config signals from the USB port of the PC when the PC is connected to the USB config port on the front panel by a standard USB cable. See USB config port for pinout details.


ARM RealView ICE grounds pin 20 of the JTAG connector. On the PB-A8, pin 20 is connected to a pull-up resistor and the nICEDETECT signal. The USB config port is automatically disabled if a JTAG emulator is connected and nICEDETECT is LOW. If you are using third-party debugging hardware, ensure that a ground is present on pin 20 of the JTAG connector.

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