DDR3 Interface

Hello.

Although I am studying the literature for this beast for almost a year now, I consider myself a newbie. Try to verify my answer.

That said, SPRS614E (http://www.ti.com/lit/ds/symlink/tms320dm8168.pdf) page 174 par 9.3 reads:

The device has a dedicated interface to DDR3 and DDR2 SDRAM. 
It supports JEDEC standard-compliant DDR2 and DDR3 SDRAM devices with the following features:

- 16-bit or 32-bit data path to external SDRAM memory
- Memory device capacity: 64Mb, 128Mb, 256Mb, 512Mb, 1Gb, 2Gb and 4Gb (x16-bit only) devices
- Support for two independent chip selects, with their corresponding register sets, and independent page tracking
- Two interfaces with associated DDR2 and DDR3 PHYs
- Dynamic memory manager allows for interleaving of data between the two DDR interfaces.

Further down the document on page 184 table 9-14 Supported DDR3 Device Combinations per EMIF  reads:

NUMBER_OF_DDR3_DEVICES DDR3_DEVICE_WIDTH_(BITS) MIRRORED? DDR3_EMIF_WIDTH_(BITS)
   1                          16                    N              16
   2                           8                    Y              16
   2                          16                    N              32
   2                          16                    Y              32
   4                           8                    N              32
   4                           8                    Y              32

So to sum it up, the most dense device you can use is something like the ISSI IS46TR16256A-15HBLA1 which is a 256x16 ==4Gbit.

Cheers.

Hello Christos,

Yes, you are correct, DM816x/AM389x device can support up to 4Gbit DDR3 chip. See also the below e2e thread:

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/717/p/121550/1042083.aspx#1042083

Note that you can have up to 8 DDR3 chips attached to the DDR3_0 (EMIF0) and DDR3_1 (EMIF1) controllers, 4 DDR3 chips to DDR3_0 and 4 DDR3 chips to DDR3_1. Also, the max total address space is 2GByte. Thus if you are planning to use 4Gbit DDR3 chips for 2Gbyte total DRAM, you can attach 2 chips to DDR3_0 and 2 chips to DDR3_1.

Regards,
Pavel