I'm trying to choose a memory with at least 32MB, but I need to be able to access it as fast as possible with my XMega128A1. Now my initial thoughts are to go with an SPI memory (http://www.spansion.com/datashee...), but I think by using DMA, I should be able to write and read from a parellel memory much faster.
Now I'm not sure if my calculations are correct :oops: . I think that if we take the SPI memory for example.
Its clock rate is approx. 100MHz(to make calculations easier :)) which is equal to .01uS
Since I have to write 8 bits command then 24 bit address and then read/write 8 bit data that is 40 clock cycles. Therefore it will take .4uS to get a byte of data. So 8bit/.4uS = 20Mbit/s is the rate to get data for the SPI memory.
I'm still looking into how to calculate the rate for teh parellel memory, but does this look correct so far?
What's your take on parellel memory vs SPI memory when working with AVR chips.