Hi,

is it possible to use PIOs as bi-directional bus?
for example: use PB0 --> PB15 of at91sam7x256 as a bus to communicate with cy7c68013a USB chip?

Hi

It is always possible to bit-bang such an interface but it is not necessarily that efficient. Since PB0..PB15 include various Ethernet pins I assume that you are not using the SAM7X due to its Ethernet controller.

It may be better to use an AVR32 with external memory interface. This will better achieve the data rates of high speed USB. (If you can't achieve these by bit-banging a parallel bus it may be just as well to use the SAM7X's internal full speed device).

Also look at the ATMEL SAM3U with built in high speed USB. It is generally easier and cheaper to use a fully integrated solution.

Regards

Mark