00:53 <zyp> oter_, I would assume the address is a direct offset into the ram; a 25 bit address for a 128 bit word can address 512MB

00:55 <zyp> to translate addr from a normal byte address to a 25-bit DMA address, I figure you'd do something like addr[4:29]

00:57 <zyp> i.e. you're not interested in the lowest four bits, since you're adressing a whole 128 bit word, and you're also not interested in the top three bits since that's just the dram offset on the main bus

00:58 <zyp> translating the other way you'd append four zero bits on the LSB end and the offset bits on the MSB end

02:08 <oter> Thanks a ton, zyp!

02:26 <oter> no dice (yet) - am not getting the value I wrote to the 0-offset rambase if I just supply 0 as the DMA read address - must be doing something else wrong in the handshake. I'

02:26 <oter> l'll keep digging in 2021 :-).