Hi All,

I need a large amount of data RAM (16M to 32M) and looking @ the cost of this amount of SRAM (and the address range of the '51), the idea of using 168 pin SDRAM DIMMs looks attractive - the're cheap & readily available.
Problem is, the're 64 bits wide & ideally need a controller.
Software control of the DIMMs would be too intensive for my application & eat up too much I/O - so a PLD seems the way to go.
The application requires endless loop storage of data, with the facility to set an address range for readback.
I envisage an 8 bit bidirectional port on the PLD to read & write data. The same port would be used to take custom commands which would be translated by the PLD to appropriate commands for the DIMMs.
Hopefully, I can utilise the DQMB (DATA INPUT/OUTPUT BYTE CONTROL)to multiplex the 64 bit data down to 8 bits.

Before I start, I'd appreciate some input - I'd hate to find I'd re-invented the wheel :)

regards