JTAG Method (PIC32M MCU):
What is 2-wire JTAG?
2-wire JTAG is a proprietary debug interface defined by Microchip. Based on 4-wire JTAG device internally, using a 2-wire converter that multiplexes the TMS, TDI, TDO JTAG lines to a single data line to the outside and demultiplexes it to the inside. Requires a special conversion unit in the device. On older devices, this conversion unit was only activated in case the device was in the special 2-wire programming mode, but did not allow full debugging using the 2-wire protocol.