PCI transactions

PCI-DDC actually uses very few PCI commands, that are listed below:

PCI-DDC responds to the configuration commands (Config Read, Config Write). All registers previously described are read and written by configuration accesses, where PCI-DDC is a fast slave, always ready, that never asks for disconnecting, retrying or aborting a transaction. Multi-data phase are allowed (burst).
PCI-DDC acts as a master to access the memory: Memory Write, Memory Read and Memory Read Multiple.
- Memory Write transaction command is used by PCI-DDC to write a packet, the LRM and the LMI.
- Memory Read command is used by PCI-DDC to read the LRM and the LPE from the memory.
- Memory Read Multiple command is used by PCI-DDC to read packets and improve performances.

PCI-DDC is not able to perform back to back transaction.

Next: Packet Formats Up: PCI-DDC programming Previous: Received Message Descriptor in