SAMA5D27 with LPDDR2 - anyone got it working?

Hi all,
We are developing a system based on one of the SAMA5 System-In-Package devices, the SAMA5D27-LD2G, which incorporates a 2Gbit LPDDR2 RAM within the same epoxy package as the MPU. Unfortunately I have not been able to make the SAMA5’s DDR-controller configure correctly and write/read data from the RAM - pretty fundamental in order to run Linux on it! We did initial development using the SAMA5D27-SOM1-EK (which has non-low-power DDR2 RAM), and had no such problems.
I’ve opened a support case with Microchip, but after an initial flurry of activity I’ve now been waiting nearly a week now for a reply from them. So…
If anyone has a working SAMA5 system with LPDDR2 RAM (either in-package or external), I’d love to hear from you!

Thanks,
Mike Haben
ASH Wireless Communications
UK

Hi @mike_haben,

Sorry, I don’t know how far you and Microchip have gone down this rabbit hole. But you did look at at91bootstrap? There is a LPDDR2 example here:

Regards,

Thanks Robert, yes, AT91Bootstrap was where we started. But both it, and the Atmel Software Pack (https://github.com/atmelcorp/atmel-software-package) have LPDDR2-initialisation code that doesn’t work , at least on our prototype boards. If only there was a SAMA5 evaluation board with LPDDRAM!

Turns out Microchip do have an evaluation board for this SIP device (photo here), but I guess it hasn’t been released yet. Apparently my code runs OK on this board when they debug using IAR Embedded Workbench - I’ve asked for a binary I can test on our hardware…

@mike_haben, that’s a real board, just no part number for us to order quite yet…

Regards,

Believe we have found the problem - our prototype design lacks a DDR_VREF signal!
The SAMA5D2-series and SAMA5D2-SIP datasheets DS60001476C and DS60001484B do not properly describe this signal. I have notified Microchip via the support case we already have open, hopefully the datasheets will be revised in due course.