The Debug option implements instruction-counting and breakpoint exceptions for debugging by software or external hardware. The option uses a high-priority interrupt level.
The sub-options described here require that Debug is selected. The Debug features are enabled either through a JTAG or APB slave port on the Xtensa processor. In each case, there is a connection to the Access Port, which provides access to the different debug functions. The Access Port implements a TAP for JTAG access, and an asynchronous peripheral slave port for APB.