STM32L471RG datasheet(55/218 Pages) STMICROELECTRONICS

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STM32L471xx

Functional overview

3.35

Development support

3.35.1

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.

Debug is performed using 2 pins only instead of 5 required by the JTAG (JTAG pins could

be re-use as GPIO with alternate function): 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.

3.35.2

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

STM32L471xx through a small number of ETM pins to an external hardware trace port

analyzer (TPA) device. Real-time instruction and data flow activity 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.

STM32L471RG データシート(PDF) 55 Page - STMicroelectronics