SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
The first write to an idle proxy thread puts the proxy thread into write mode for the selected channel. Further legal writes are stored in the buffer for the enabled bytes and offset within the buffer. A write to a previously written location will overwrite the previous data. The buffer is not cleared initially, so if a byte is not written, the message will include previous buffer data. When there is a legal write to the last byte of the resource, then the entire data is written by the proxy to the target and channel as a single write burst. The proxy will wait for the write status from the target write before it sends the write status for this final byte host write. This allows the host to use the write status to guarantee the entire write data from the proxy has landed at the target. The proxy thread is then put back into idle state. A write completion when there are no credits available results in the message not being written to the resource and the proxy thread remains in write mode (so that the message can be quickly completed when a credit becomes available).