Datasheet

Functional overview STM32F20xxx
38/178 DocID15818 Rev 11
3.37 Serial wire JTAG debug port (SWJ-DP)
The ARM SWJ-DP interface is embedded, and is a combined JTAG and serial wire debug
port that enables either a serial wire debug or a JTAG probe to be connected to the target.
The JTAG TMS and TCK pins are shared with SWDIO and SWCLK, respectively, and a
specific sequence on the TMS pin is used to switch between JTAG-DP and SW-DP.
3.38 Embedded Trace Macrocell™
The ARM Embedded Trace Macrocell provides a greater visibility of the instruction and data
flow inside the CPU core by streaming compressed data at a very high rate from the
STM32F20x through a small number of ETM pins to an external hardware trace port
analyzer (TPA) device. The TPA is connected to a host computer using USB, Ethernet, or
any other high-speed channel. Real-time instruction and data flow activity can be recorded
and then formatted for display on the host computer that runs the debugger software. TPA
hardware is commercially available from common development tool vendors.
The Embedded Trace Macrocell operates with third party debugger software tools.