Re-order buffer for in-order execution of dependent write transactions

Abstract

Techniques are described for maintaining in-order execution when a dependency exists between write transactions. In some embodiments, a write re-order buffer (WROB) is configured to assign the same group ID to an incoming write transaction upon determining that the incoming write transaction is dependent on a pending write transaction. The WROB forwards the incoming write transaction to an interconnect fabric for routing to a completer device. The interconnect fabric enforces in-order execution when write transactions share the same group ID. The WROB can maintain a transaction log of pending write transactions and also track the statuses of responses for such transactions. Transaction responses can include responses sent from a completer to confirm that a transaction has actually been completed. Additionally, the WROB can send a response indicating completion back to the requester of the transaction. In some embodiments, the WROB is configured to send an early response to the requester.