SRAM vs SDRAM

Hi Mark,

> Do you use the PSRAM as a simple SRAM replacement (in which mode it has

> quite slow 70ns access times) or do you make use of the Burst mode to get much

> faster average access rates?

I use it as a simple SRAM replacement. As for the access times ... on the board I was

referring to, I was (continue) to use a 50 MHz clock. So compared to SDRAM with

anything more than 3.5 clocks per access, the PSRAM isn't slow ;-). And I observed

SDRAM performance that was _much_ worse than that. Aside from the extra pins,

the PSRAM was ideal for the application -- and I was able to move to a lower

density FPGA.

Also, to be fair, I haven't re-visited the matter -- so I don't know if the SDRAM

controller has improved.

>I've been tinking about knocking up an interface block to access it in burst mode

Same here ... I'm thinking the same for our new board. But unfortunately, like many

other things ... it's still just thinking. ;-) This might be a good candidate to add to

a wish list for the Altera design teams.

Regards,

--Scott