I am wanting to put some mobile sdram (MT48H4M16LF) in to deep power down mode using the C5505. However, It does NOT seem to put the sdram lines in to the proper state for this happen.
From the MT48H4M16LF data sheet:
Deep power-down is an operating mode used to achieve maximum power reduction by
eliminating the power to the memory array. Data is not retained after the device enters
deep power-down mode.
This mode is entered by having all banks idle then CS# and WE# held LOW with RAS#
and CAS# held HIGH at the rising edge of the clock, while CKE is LOW. This mode is
exited by asserting CKE HIGH.
However, when I set the PD bit in SDCR2 register when the CKE lines goes low, I see the RAS#, CAS#, go low and the WE# line high.
I would have expected something similar to page 2 of
http://www.samsung.com/global/business/semiconductor/products/dram/downloads/applicationnote/mobile_dpd_rev0.pdf
Since the MT48H4M16LF is called out in the EMIF user guide (sprugu6), I expected to be able to the sdram in to deep sleep mode right out of the box.
I set the EMIF register like those in the GEL file, I then write a 0x4000 to the SDCR2 register.
Has anyone been able to do this successfully? Am I doing something wrong?
Cheers!
