AVR-Chat

On Sep 18, 2008, at 6:21 PM, David VanHorn wrote:

>> Ideally, "read a 400 MB file sequentially from start to end, then  
>> stop."
>
> What I'm asking is wether you need to actually READ those bytes, or
> just cause them to go from one device to the other, external of the
> AVR.
> This might be solvable with some simple hardware.

You are asking whether I have to read *and* write the data. "No." If I  
can source a clean clock off the AVR and have a steady data stream  
coming off an SD card via SPI then the AVR doesn't have to re-write  
the data to another device. But this means there can be no pauses. The  
clock and data must never stop.

Could put a serial FIFO between the data and my output. Clock the  
output of the FIFO with a continuous 10 MHz clock. Clock the SD even  
faster while controlling chip select on the FIFO input to keep control  
information from being sent to the other device. But last time I  
checked hardware FIFO chips were not cheap. I'd be of a mind to  
upgrade my CPU and handle it there rather than add expensive or rare  
hardware.

--
David Kelly N4HHE, dkelly@HiWAAY.net
========================================================================
Whom computers would destroy, they must first drive mad.