topic FRDM-MCXE31B in MCX Microcontrollers https://community.nxp.com/t5/MCX-Microcontrollers/FRDM-MCXE31B/m-p/2408846#M5839 <P>&nbsp;</P><P>I'm trying to debug/flash a FRDM-MCXE31B board and consistently hit a RAM initialization failure during the connect sequence, before any application code loads. I've ruled out wiring, cables, USB ports, jumpers, and probe firmware — details below.</P><P><STRONG>Setup:</STRONG></P><UL><LI>Board: FRDM-MCXE31B</LI><LI>M C U: MCXE31B</LI><LI>Tested with: M C U X Presso IDE v25.6 (Windows) and standalone Link-server v26.6.137 (Ubuntu Linux) — same failure on both</LI><LI>MCU-Link onboard probe firmware: updated to v3.172 (confirmed matching, no version mismatch reported)</LI><LI>Connect script: MCXE31x_connect.scp</LI></UL><P><STRONG>What works:</STRONG></P><UL><LI>SWD physical connection succeeds</LI><LI>Debug authentication/unlock succeeds ("application debug already enabled")</LI><LI>Chip identification succeeds — reads back correct part number:</LI></UL><DIV><DIV><DIV><DIV>&nbsp;</DIV></DIV><DIV><PRE>SIUL2:MIDR1 @ 0x40290004 = 0x6BA02477 MCU Part Number is 0x000003A0</PRE></DIV></DIV></DIV><P><STRONG>Where it fails — every attempt, both OSes:</STRONG></P><DIV><DIV><DIV><DIV>&nbsp;</DIV></DIV><DIV><PRE>... RAM init via eDMA: address=0x20400000 size=0x00028000 Error: Wire Ack Fault - target connected? [repeats ~46 times] Error: RAM initialization failed (timeout)!</PRE></DIV></DIV></DIV><P>This leads to: Failed on connect: Ep(01). Target marked as not debuggable.</P><P><STRONG>Context I found that may be relevant:</STRONG> I understand from the S32K3 reference manual (same architecture family) that ECC-protected RAM on these parts must be initialized via a 64-bit master write before any 32-bit access is valid after power-on-reset — so I assume this eDMA step in the connect script is performing that mandatory initialization automatically. It appears to be this automated step itself that's timing out, not a wiring/connection issue, since chip identification (steps before this) succeeds cleanly every time.</P><P><STRONG>Question:</STRONG> Has anyone else hit this specific failure on FRDM-MCXE31B? Is there a known workaround, updated connect script, or a way to skip/adjust the automatic RAM-init step? Happy to provide full verbose logs (Link-server -l 5) if useful.</P> Thu, 27 Aug 2026 10:16:13 GMT Lokeshgowdas 2026-08-27T10:16:13Z FRDM-MCXE31B https://community.nxp.com/t5/MCX-Microcontrollers/FRDM-MCXE31B/m-p/2408846#M5839 <P>&nbsp;</P><P>I'm trying to debug/flash a FRDM-MCXE31B board and consistently hit a RAM initialization failure during the connect sequence, before any application code loads. I've ruled out wiring, cables, USB ports, jumpers, and probe firmware — details below.</P><P><STRONG>Setup:</STRONG></P><UL><LI>Board: FRDM-MCXE31B</LI><LI>M C U: MCXE31B</LI><LI>Tested with: M C U X Presso IDE v25.6 (Windows) and standalone Link-server v26.6.137 (Ubuntu Linux) — same failure on both</LI><LI>MCU-Link onboard probe firmware: updated to v3.172 (confirmed matching, no version mismatch reported)</LI><LI>Connect script: MCXE31x_connect.scp</LI></UL><P><STRONG>What works:</STRONG></P><UL><LI>SWD physical connection succeeds</LI><LI>Debug authentication/unlock succeeds ("application debug already enabled")</LI><LI>Chip identification succeeds — reads back correct part number:</LI></UL><DIV><DIV><DIV><DIV>&nbsp;</DIV></DIV><DIV><PRE>SIUL2:MIDR1 @ 0x40290004 = 0x6BA02477 MCU Part Number is 0x000003A0</PRE></DIV></DIV></DIV><P><STRONG>Where it fails — every attempt, both OSes:</STRONG></P><DIV><DIV><DIV><DIV>&nbsp;</DIV></DIV><DIV><PRE>... RAM init via eDMA: address=0x20400000 size=0x00028000 Error: Wire Ack Fault - target connected? [repeats ~46 times] Error: RAM initialization failed (timeout)!</PRE></DIV></DIV></DIV><P>This leads to: Failed on connect: Ep(01). Target marked as not debuggable.</P><P><STRONG>Context I found that may be relevant:</STRONG> I understand from the S32K3 reference manual (same architecture family) that ECC-protected RAM on these parts must be initialized via a 64-bit master write before any 32-bit access is valid after power-on-reset — so I assume this eDMA step in the connect script is performing that mandatory initialization automatically. It appears to be this automated step itself that's timing out, not a wiring/connection issue, since chip identification (steps before this) succeeds cleanly every time.</P><P><STRONG>Question:</STRONG> Has anyone else hit this specific failure on FRDM-MCXE31B? Is there a known workaround, updated connect script, or a way to skip/adjust the automatic RAM-init step? Happy to provide full verbose logs (Link-server -l 5) if useful.</P> Thu, 27 Aug 2026 10:16:13 GMT https://community.nxp.com/t5/MCX-Microcontrollers/FRDM-MCXE31B/m-p/2408846#M5839 Lokeshgowdas 2026-08-27T10:16:13Z Re: FRDM-MCXE31B https://community.nxp.com/t5/MCX-Microcontrollers/FRDM-MCXE31B/m-p/2408991#M5842 <P>Hi&nbsp;<a href="https://community.nxp.com/t5/user/viewprofilepage/user-id/265994">@Lokeshgowdas</a>&nbsp;</P> <P>Thank you for your post!</P> <P>Is this happening only in one project?&nbsp;</P> <P>I see that your project is using Zephyr, could you please share which version are you using?</P> <P>Please share the logs to review it.&nbsp;</P> <P>&nbsp;</P> Thu, 27 Aug 2026 18:27:14 GMT https://community.nxp.com/t5/MCX-Microcontrollers/FRDM-MCXE31B/m-p/2408991#M5842 carlos_o 2026-08-27T18:27:14Z