SWD Interface

The SAM-ICE support ARM's Serial Wire Debug (SWD). SWD replaces the 5-pin JTAG port with a clock (SWDCLK) and a single bi-directional data pin (SWDIO), providing all the normal JTAG debug and test functionality. SWDIO and SWCLK are overlaid on the TMS and TCK pins. In order to communicate with a SWD device, J-Link sends out data on SWDIO, synchronous to the SWCLK. With every rising edge of SWCLK, one bit of data is transmitted or received on the SWDIO.