2.2. SWJ-DP

The SWJ-DP is a combined JTAG-DP and SW-DP that enables you to connect either a Serial Wire Debug (SWD) or JTAG probe to a target. It is the standard CoreSight debug port, and enables access either to the JTAG-DP or SW-DP blocks. To make efficient use of package pins, serial wire shares, or overlays, the JTAG pins use an autodetect mechanism that switches between JTAG-DP and SW-DP depending on which probe is connected. 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, it behaves as a dedicated JTAG-DP or SW-DP depending upon which sequence had been performed.


For more information about the programming capabilities and features of the SWJ-DP, see the JTAG-DP and SW-DP sections in JTAG-DP and SW-DP.

Figure 2.6 shows the external connections to the SWJ-DP.

The SWJ-DP is described in:

Figure 2.6. SWJ-DP external connections

Copyright © 2004-2009 ARM. All rights reserved.ARM DDI 0314H