Re: USB enumeration

From: Andrew Jackson <alj@xxxxxxxxxx>
Date: Thu, 31 Jul 2008 16:54:57 +0100

I'm desining a USB CDC (communication device class) device using
MAX3420. The configuration descriptor is 67 bytes long. for Full-speed
operation maximum payload in a packet is 64 bytes. Does anyone know
how to send 67bytes to the host's request?
The USB spec says you can do it by sending 64bytes + remaining bytes
and Zero-length-packet. I'didn't quite get that. If anyone come
accross this before, please help me.

Assuming that your device descriptor has specified a control endpoint (endpoint 0) size of 64, you send it as a 64 byte packet and a 3 byte packet (which is "short").

Andrew
.

References:
- USB enumeration
  - From: Thanushan

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