TMS570LS1227: SEGGER J-Link Usage with Cortex-R

Jacob Byers

Part Number: TMS570LS1227
Other Parts Discussed in Thread: CCSTUDIO

Hello,

I am shifting from the XDS100V2 to the Segger Jlink Pro (ethernet) for debugging, but am having some issues getting it working with CCS.

I can connect to the debugger through CCS with no additional JLinkScript files used, but consistently get "Break at address 0x0" and cannot meaningfully debug without power-cycling the TMS570. Even so, I am unable to read memory or variables without pausing execution (as described here: TMS570LS1227 debug with SEGGER's JLINK - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums ).

I've followed the segger documentation for integration with Code Composer Studio, to include the inclusion of the ECC initialization skip script provided (see link below):

I have used the V9.80 and V7.98 JLink Drivers with little discernable difference in outcome. When I specify the provided JLinkScript file that skips ECC initialization (to achieve my goal of connecting to the running target), I get a error that indicates a target endianness mismatch (this is not a true error).

For transparency, I have been seemingly unable to add JLink through the CCS package manager. I get similar issues to here: https://e2e.ti.com/support/tools/code-composer-studio-group/ccs/f/code-composer-studio-forum/923260/ccs-adding-j-link-debugger-to-ccs I seem to have been able to get around this by replacing the dll directly in code composer studio with the up to date version from SEGGER.

I (and several coworkers) tried this on CCS 10.4, 12.8, and 11.0 with similar results.

Do you have any advice on how to proceed?

6 days ago

0 jagadish gundavarapu 6 days ago

TI__Guru* 80106 points

Hi Jacob,

I never came across this issue before, on first level could you please verify below of our internal AI suggestions:

Issue 1: "Break at Address 0x0" on Connect

This is almost always caused by one of the following:

Root Cause A: ECC Initialization Conflict

The TMS570LS1227 runs a hardware ECC initialization routine in ROM before reaching your code. The J-Link interrupts this and lands at 0x0.

Fix - Verify your JLinkScript is actually being loaded:

// In CCS Debug Configuration:

// Target > J-Link > JLinkScript file field

// Confirm the FULL absolute path is specified, not relative

// e.g., C:/JLink/Scripts/TI_TMS570Lx_SkipECCInit.JLinkScript

Check the J-Link log output in CCS console for:

Script: Found and executed

If you do NOT see this, the script is silently failing to load.

Root Cause B: Reset Handling Misconfiguration

In your CCS Debug Configuration, verify these settings under Target > Reset Configuration:

Setting	Recommended Value
Reset Type	Core Reset (not System Reset)
Reset at connect	Disabled initially for live debug
Halt after reset	Disabled for connect-to-running

Issue 2: Endianness Mismatch Error When Using JLinkScript

This is the key issue and is likely masking everything else.

What's Actually Happening

The TMS570LS1227 is a big-endian Cortex-R4F. The J-Link drivers sometimes misidentify endianness when a JLinkScript modifies the connection sequence.

Verify your .ccxml target configuration:

JLinkScript Endianness Declaration

The provided SEGGER script may be missing or have an incorrect endianness declaration. Open TI_TMS570Lx_SkipECCInit.JLinkScript and verify/add:

// At the top of the JLinkScript file

int InitTarget(void) {

// Explicitly declare big-endian

JLINK_ExecCommand("SetEndian big");

// ... rest of ECC skip code

return 0;

}

If the script does not contain this, add it as the first line of InitTarget().

Issue 3: Cannot Read Memory/Variables Without Halting

This is a real-time memory access limitation with the J-Link on TMS570.

Enable DAP-Based Non-Intrusive Access

In CCS Debug Configuration under J-Link settings:

Enable "Non-intrusive (SWO/SWV)" → Disabled (TMS570 doesn't support SWO)

Enable "Allow memory access during run" → Check if available

Alternative: Use ARMV7 DAP Directly

In your .ccxml, try forcing the connection through DAP:

</connection>

Note: The TMS570LS1227 does NOT support true run-time memory access without the ETM/ETB infrastructure being configured. This is a silicon limitation, not a J-Link limitation. The XDS100V2 had the same restriction but handled it differently through TI's proprietary ICEPICK router.

Issue 4: CCS Package Manager Failure / Manual DLL Replacement

This is likely the root cause of several downstream issues.

Proper Manual Integration Steps

Rather than replacing the DLL directly (which causes version conflicts), do the following:

Step 1: Install J-Link software from SEGGER separately
Step 2: In CCS, go to:

Window > Preferences > Code Composer Studio > Debug > GDB SEGGER J-Link Debugging

Step 3: Point CCS to the installed J-Link directory explicitly:

C:/Program Files/SEGGER/JLink_V798/

Step 4: Do NOT mix DLLs between CCS internal versions and SEGGER installed versions. Remove any manually placed DLLs from:

[CCS Install]/ccs/ccs_base/DebugServer/drivers/

Recommended Complete Debug Configuration

Connection: SEGGER J-Link

Device: TMS570LS1227ZWT ← Verify exact part suffix

Interface: JTAG

Interface Speed: 1000 kHz (start low, increase after stable)

JLinkScript: [full path]/TI_TMS570Lx_SkipECCInit.JLinkScript

Reset: Core Reset

Halt on connect: NO (for connect-to-running)

Recommended Troubleshooting Sequence

1. Remove all manually placed DLLs from CCS directories

2. Reinstall J-Link V7.98 cleanly from SEGGER

3. Point CCS Preferences to the SEGGER install directory

4. Create a fresh .ccxml using CCS Target Configuration editor

5. Add SetEndian big to JLinkScript InitTarget()

6. Set Interface Speed to 1000 kHz

7. Disable all reset-on-connect options

8. Connect and check J-Link log for script execution confirmation

If All Else Fails: J-Link GDB Server Approach

Bypass CCS's J-Link integration entirely:

# Launch J-Link GDB Server manually

JLinkGDBServer.exe -device TMS570LS1227 -endian big \

-if JTAG -speed 1000 -scriptfile TI_TMS570Lx_SkipECCInit.JLinkScript

# Then connect CCS to localhost:2331 via GDB

This isolates whether the issue is CCS integration or the J-Link connection itself.

--
Thanks & regards,
Jagadish.

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