TMS320C6678: C6678 DDR3 obsolete parts

Simone Nodari

Part Number: TMS320C6678

Hi to all,

we were using MT41K256M16HA-125:E (DDR3-1600) on a previous release of a custom DSP TMS320C6678 based board.

The memories were working at 1066Mbit (533Mhz) without issues.

Those memories are now obsolete, so we need to replace them with the following suggested part number: MT41K256M16TW-107 IT:P (DDR3-1866).

Are those new devices supported using the same working frequency (1066Mbit i.e. 533Mhz) as the previous used ones?

On sprabi1b.pdf (DDR3 design requirements for keystone devices) there are no mention relating to DDR3-1866 devices.

Thanks in advance,

Simone

over 6 years ago

0 Yordan Kovachev over 6 years ago

TI__Guru**** 161600 points

Hi,

I've notified the design team. Their feedback will be posted directly here.

Best Regards,
Yordan

0 Bill Taboada over 6 years ago

TI__Mastermind 42545 points

Hi Simone,
The DDR3 specification requires that faster parts be compatible with lower clock speeds and that DDR3L parts operate with the IO voltage levels needed by DDR3. This results in memory manufacturers obsoleting slower memories once the faster memories become available. We don't have the resource to update these documents as fast as the memory parts become obsolete. You should be able to operate the 1866 parts at 1066 in your design but you should enter the information from the DDR3 data sheet into the REGCALC spreadsheet to see if any of the register settings for the DDR3 subsystem need to be changed in your initialization.
Regards, Bill

0 Simone Nodari over 6 years ago in reply to Bill Taboada

Prodigy 30 points

Thanks Bill,

I'll try with the current timing setup, I hope that it'll works without problems.

Simone.

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TMS320C6678: C6678 DDR3 obsolete parts