| ??? 01/21/06 18:03 Modified: 01/21/06 18:05 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#107992 - ZLP?? Responding to: ???'s previous message |
Mehdi said:
I send a zero length packet after acknowledge setup command to both of control in and control out. a) What sequence did you use to issue the ZLP (Zero-Length Packet)? Philips C example uses following sequence to send ZLP. Actually, it uses the same 'D12_WriteEndpoint' routine as usual. Is it same as yours? - 'Select Endpoint' + read an optional byte - 'Write buffer' - - 0 (reserved byte) - - 0 (length) - - (no data bytes) - 'Validate buffer' b) ZLP to Control OUT? It is unusual to write to the Control Out buffer, either ZLP or not. Can you get Control IN interrupt without writing to control OUT? c) Status of Control IN What code returns on 'Read last transaction status register' command to Control IN, when interrupt occurs? Ummm... if a bus analyzer is available, we can realize the problem more clearly... software analyzer doesn't work until enumeration finished. Tsuneo |
