Talk:RDRAM Interface
--Rasky (talk) 17:51, 30 August 2021 (UTC)
(SwapField[8:0] x Adr[19:11]) + ~SwapField[8:0]xAdr[28:20]
Does this mean:
(SwapField[8:0] & Adr[19:11]) | (~SwapField[8:0] & Adr[28:20])
That is, is the SwapField used as a way to swap bits between lower byte and upper byte?
Yes, it is used to exchange on bit-by-bit basis upper and lower bits of Adr. This allows to move some bits addressing bank's row upper in the address to spread memory accesses among RDRAM modules and benefit from internal row caching done by the RDRAM module. You can look in the datasheets linked in the RDRAM page a description of what it does.