Hello NXP-Team, hello Forum,
we have a custom addapted iMX8mq-based board with 3G, running without any complains.
Due to a LPDDR-memory discontinuation, we changed our LPDDR-Memory.
Current LPDDR is: MT53B768M32D4NQ-062
New LPDDR is: MT53E768M32D2ZW-46
https://www.farnell.com/datasheets/4000640.pdf
We rerun the DDR-StressTest to configure the correct parameters of our new LPDDR
The new LPDDR size is indicated in Excel sheet as expected with 24Gb
But after loading the exported DDR-Script into NXP DDR Tool, the LPDDR size is announced with 1576MB.
We expeted 3072MB per Controller / of the board.
The DDR Stresstest is completed successfully, the Memory can be accessed up to the 3GB adresses within DDR-Tool (0x40000000 to 0xFF000000),
In U-Boot, where we changed only the adapted DDR-Setting (code exported from DDR-Tool), runs without any Problem.
But Linux boot fails (U-Boot's "Starting kernel ...." is the last reported info)
What is the reason of the unexpected 1536MB memory announcment in DDR Tool, which is not according to the 3GB announced by MX8M-RPA-Excel sheet?
Is there a misconfiguration, leading to the linux start failure?
We are using i.MX 8M Family DDR Register Programming Aid (RPA), v33.
Thank you for all your efforts
N. Wiedmann
Thank you, that is the reason for the incompatibility of the MT53E768M32D2ZW-46
The LPDDR needs 17 row bits to address its number of 98304 rows
According to the linked 'memory compatibility guide', the i.MX 8M Quad is limited to 16 row bits.
N. Wiedmann
Hello Salas,
thank you for responding.
I tried with the Config Tools v15 (selected CPU, completed in the fields in DDRC-Tab, exported .ds and lpppdr4_timing.c file).
The StressTestTool still reports the 'incorrect' LPDDR-size 1536MB (instead of 3072), U-Boot is running, Linux doesn't start.
Could there be an issue with the "Number of ROW-Adresses"?
The 'MT53E768M32D2ZW-46' data sheet reports R[16:0], the ExcelSheet blocks >16, in ConfigTool we tried 17, but it doesn't change the reported LPDDR-size
Best regards,
N. Wiedmann
