SDRAM read/write example

[quantrpeter]

hi, is there any SDRAM read/write example? thanks

[caffiend13]

I used the SDR SDRAM Advanced Controller from the Lattice site, then modified it with the correct timing parameters and changed it from doing 4 burst read/writes of 4 bits each to one burst of 16 bits. Then I wrote my own module to trigger the r/w enable. Of any example SDR SDRAM controller I've tried, this was the only one I got to work.

You will need to fuss with it, but it will work (and you will be forced to read and re-read the SDRAM data sheet, which isn't a bad thing).

The one thing that I did not understand before was the initialization procedure. Most controller examples use SDRAMs that only need two refresh cycles during initialization. The one on the iCESugar-Pro needs at least 8. So you will need to modify the Lattice design to do that.

https://www.latticesemi.com/products/designsoftwareandip/intellectualproperty/referencedesigns/referencedesign04/sdr-sdram-controller-advanced