Send multiple naks or just once?

[ulao]

I was wondering if sending a NAK to the host tells it, I'm busy until the the device sends ACK. In other does a device typical keep sending NAK, NAK, NAK, NAK, NAK, NAK, ACK... or NAK, .....................ACK.

[Jan Axelson]

Endpoints can only respond to communications from the host and must return NAK (or NYET) in repsonse to IN or OUT token packets until they have data ready to send or are able to receive new data.