As mentioned in the docs and quoted by Sammy Z, NC_WRITE_SUCCESS is a state, not an event. Think of it as a state machine... There is the NC_WRITE_SUCCESS state and there is a different state, we can call it X.
NC_WRITE_SUCCESS state indicates that the transfer mechanism is idle. If any transfers had been queued up, they have been transmitted successfully on the bus.
X state indicates that the transfer mechanism is busy, or that the last transfer (if single-shot TX is true) didn't transmit successfully on the bus.
The transitions are as follows:
pon -> NC_WRITE_SUCCESS
ncWrite transistions from NC_WRITE_SUCCESS to X
tx complete and write queue is empty X to NC_WRITE_SUCCESS
tx complete and write queue is not empty X to X
tx failed X to X (typically, this will get retried until write is successful, but it may never be successful)
The notification is not based on a transition, but based on being in a state. At pon, you are in the write success state - if it helps, you can rename this state in your head to be transfer mechanism idle - if that helps to realize that you are in this state even if you have never sent a frame across the bus.
After writing a frame, you will go back into the NC_WRITE_SUCCESS state once it is transmitted completely - which is, what I guess, you want to see, so you would be best waiting until after a write to enable the notification.
