66AK2G12: Is there an updated version of sprabx7 (K2 DDR3 Register Calc v1p60.xlsx)?

David Knowles

Part Number: 66AK2G12
Other Parts Discussed in Thread: EVMK2GX,

My EVMK2GX board uses MT41K512M8DA-107 (DDR3L) parts, which is speed grade 1866.

The spreadsheet will only let you choose 800, 1066, 1333 or 1600, and it is password protected, and won't allow adding an additional choice.

Our custom hardware we plan to use MT41K512M16VRP-107 DDR parts, (also speed grade 1866) and I'd like to check my understanding of the DDR initialization.

The supplied gel file seems to work on the EVM, and the register values used match the example values in SPRABX7.pdf, so I suspect at some time, someone figured out how to initialize this part.

But I don't seem to be able to enter values from the DDR3L datasheet into the spreadsheet, and get the register values used in the .gel file (or the example in sprabx8.pdf).

11 months ago

0 David Knowles 11 months ago

Prodigy 20 points

I may have stumbled across the answer in another thread, although it was not perfectly clear.
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/846886/66ak2g12-how-to-set-the-speed-grade-1866-to-calc-v1p60-xlsx

Although the MT41K512M8DA-107 DDR3 parts are capable of speeds up to 1866, the 66AK2G12 is not. The datasheet for the 66AK2G12 - Table 5.1 implies that the fastest 66AK2G12 part is only capable of interfacing to 1066 speed grade memory (DDR3).

https://www.ti.com/lit/gpn/66ak2g12

The datasheet for MT41K512M8DA-107 https://www.mouser.com/datasheet/2/671/4Gb_DDR3L-1283964.pdf contains a table of "speed bins" for 1066 speed grades.

By selecting "User Defined", and entering in the Design Parameters from the datasheet for 1066 speeds, I was able to generate register settings that seemed to match what was being programmed by the gel file (evmk2g.gel).

It seems like it would be really helpful if those values were actually a column in the spreadsheet, instead of forcing a user to look them up in the datasheet and enter them.

Could someone verify that my conclusion here is correct?

+1 JJD 11 months ago in reply to David Knowles

TI__Guru* 76380 points

Hi David, the web version of the tool is the latest. I think your overall conclusion is correct. You have to separate out speed grade of the device (in your case DDR3L-1866) vs operating data rate (in your case DDR3L-1066, which is the maximum data rate for 66AkG12). Most higher speed grade DDR3L devices are backward compatible and can operate at slower frequencies. In Table 56 of the datasheet you link, one of the notes says it is backward compatible to 1066.

Regards,

James

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66AK2G12: Is there an updated version of sprabx7 (K2 DDR3 Register Calc v1p60.xlsx)?