What is the lowest power state for LPDDR SDRAM?

[nathanpalmer]

I have a legacy design that includes an iMX27 and LPDDR.  I am trying to take some measurements of the system power with various components powered off (or close to it) to calculate board overhead.  

I would like to disable the SDRAM, but I don't know if just not configuring it is enough to set it in the lowest power mode.  I am running application code from internal SRAM so I don't need the SDRAM at all.  How do I power it off (or close to off) from the iMX27?  Is there a mode I can put the SDRAM in that is essentially off?

Thanks!

[Yuri · Accepted solution]

Please use section 18.4.5 (Low Power Operating Modes) of the i.MX27 Reference Manual.
You can try Self Refresh Mode (section 18.4.5.1 Self Refresh Mode for SDRAM/LPDDR Devices)
or

Precharge Power Down Mode (section 18.4.5.3 Precharge Power Down Mode).