Debug Management; Introduction; Swj Debug Port (Serial Wire And Jtag); Pinout And Debug Port Pins - ST STM32L152-EVAL Application Note

Debug management

5 Debug management
5.1

Introduction

The host/target interface is the hardware equipment that connects the host to the application
board. This interface is made of three components: a hardware debug tool, a JTAG or SW
connector and a cable connecting the host to the debug tool.
Figure 12
(STM32L152-EVAL) embeds the debug tools (ST-LINK) so it can be directly connected to
the PC through an USB cable.

Figure 12. Host-to-board connection

5.2

SWJ debug port (serial wire and JTAG)

The STM32L1xxx core integrates the serial wire/JTAG debug port (SWJ-DP). It is an ARM®
standard CoreSight™ debug port that combines a JTAG-DP (5-pin) interface and a SW-DP
(2-pin) interface.
●
The JTAG debug port (JTAG-DP) provides a 5-pin standard JTAG interface to the AHP-
AP port
●
The serial wire debug port (SW-DP) provides a 2-pin (clock + data) interface to the
AHP-AP port
In the SWJ-DP, the two JTAG pins of the SW-DP are multiplexed with some of the five JTAG
pins of the JTAG-DP.
5.3

Pinout and debug port pins

The STM32L1xxx MCU is offered in various packages with different numbers of available
pins. As a result, some functionality related to the pin availability may differ from one
package to another.
20/30
shows the connection of the host to a development board. The evaluation board
Doc ID 17496 Rev 5
AN3216