Datasheet

GND

TDI

TDO

TCK

TMS

Install Jumper

Debug and Virtual COM Port (Schematic Page 4)

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2.4 Debug and Virtual COM Port (Schematic Page 4)

2.4.1 In-Circuit Debug Interface (ICDI)

The DK-TM4C123G development board comes with an on-board In-Circuit Debug Interface (ICDI). The

ICDI allows for programming and debugging of the TM4C123GH6PGE using LM Flash Programmer

and/or any of the supported tool chains. Both JTAG and Serial Wire Debug (SWD) are supported.

An external debugger can be connected to the development board through the 2 x 5 fine pitch (0.05”)

ARM JTAG header (J1). When connecting an external debugger, pin 3 of the JTAG header must be tied

to ground in order for the ICDI to release control of the JTAG signals. The ARM standard pinout specifies

pin 3 as ground, therefore, any standard third-party debugger should work.

Table 2-13 shows the pins used for JTAG and SWD.

Table 2-13. In-Circuit Debug Interface (ICDI) Signals

GPIO Pin Pin Function JTAG Header Pin

PC0 TCK/SWCLK 4

PC1 TMS/SWDIO 2

PC2 TDI 8

PC3 TDO/SWO 6

RST RST 10

ICDI Function

- EXTDBG 3

See Appendix A: Schematics for the full header pinout.

In addition, the ICDI can debug an external target using the header locations near the JTAG connector.

The on-board TM4C123GH6PGE must be held in reset by installing a 2-pin jumper in the DEBUG OUT

EN jumper position (JP1). The HIB DISC (located near the SELECT/WAKE button) is a conveniently

available jumper to repurpose. The following diagram illustrates how an external target can be connected.

In this configuration, the debugger will not have control of the hardware reset line RST.

Figure 2-3. Debug Out

Hardware Description SPMU357B–August 2013–Revised March 2014

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