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SAMA5 single DDR module?

Posted: Wed Nov 08, 2017 8:26 pm
by engin
Hi,

I did some work about measuring the power consumption of SAMA5D2 Xplained board, and I found there is 38mA @ VDD_5V in ultra low power mode.
I guess the major point is due to DDR power consumption in self-refresh mode.
There is a comparison table 3.3 in the document http://www.atmel.com/Images/Atmel-11291 ... n-note.pdf which give an actual data that DDR2 takes about 28.8mA @ 1.8V in self-refresh mode for each module.
So my question is: is it possible to use only one DDR2/DDR3 module with SAM-A5 solution if we can customize our board? is there any similar reference/evaluation board designed? How to modify the configuration of at91bootstrap & u-boot & at91-linux?

Thanks,

-Engin

Re: SAMA5 single DDR module?

Posted: Thu Nov 09, 2017 1:30 am
by blue_z
engin wrote:So my question is: is it possible to use only one DDR2/DDR3 module with SAM-A5 solution if we can customize our board?
Memory "module" or memory chip?
The SAMA5D2 datasheet clearly states that it has 16-bit or 32-bit external interface.
Sixteen-bit mode would reduce both performance and maximum memory capacity.

If you're concerned about power consumption, then why aren't you looking at low-power memory?

engin wrote: How to modify the configuration of at91bootstrap & u-boot & at91-linux?
The external dynamic memory configuration is typically performed in AT91Bootstrap.
Study Implementation of SDRAM on SAMA5D2x Devices.

Regards

Re: SAMA5 single DDR module?

Posted: Thu Nov 09, 2017 5:02 am
by engin
Hi Blue_z,

My apology, I mean single memory chip.
We know there is LPDDR2 solution, but, as you know, its price is double than standard DDR2.
So we are thinking how to use single memory chip, no matter it is DDR2 or LPDDR2.
For example, is it possible to replace DDR3L(128Mx16bit)x2 to LPDDR2(128Mx32bit)x1 on SAMA5D2 board?
I would assume that power consumption of double chip is more than single chip, is that correct?

Thanks,

-Engin

Re: SAMA5 single DDR module?

Posted: Thu Nov 09, 2017 11:23 pm
by blue_z
engin wrote:... but, as you know, its price is double than standard DDR2.
Actually no, I do not keep tabs on component prices.
engin wrote:For example, is it possible to replace DDR3L(128Mx16bit)x2 to LPDDR2(128Mx32bit)x1 on SAMA5D2 board?
I'm not qualified to give advice on board design.

Regards