I have designed a CardBus Design, which is very similar to pci with full master functionality. The main aim of this card is to transfer a huge amount of data to and from PC RAM to the CardBus card. But in master read mode I very often get a target retry. The fact of an target retry (in this case the pc is the target) is not abnormal but I have scanned the pci bus and I have seen a lot of target retries in series
-> sometimes more then 100 in a row. This is absolute unacceptable due to the poor bus performance -> so my fifo's run out of data. The common pc memory (ram) is locked from driver and is set as non cacheable.
I hope that somebody can help me in this issue. I am not really sure if this is a hardware or a software (driver) problem.
With kind regards Nico Presser