SPRUJF2A March 2026 – March 2026 AM13E23019
The SWJ-DP is a combined JTAG-DP and SW-DP that interfaces directly with a SWD or JTAG probe to connect to a target by enabling access to the SW-DP or JTAG-DP blocks. The SWJ-DP interface requires four connections:
To make efficient use of package pins, serial wire shares, and overlays, the JTAG pins use an autodetect mechanism that switches between JTAG-DP and SW-DP depending on which probe is connected. By default on POR, the JTAG-DP is used to enable JTAG debug access. A special sequence on the SWDIOTMS pin is used to switch between JTAG-DP and SW-DP. When the switching sequence has been transmitted to the SWJ-DP, the interface behaves as a dedicated JTAG-DP or SW-DP depending upon which sequence had been performed.