Re: [Fx2lib-devel] Arming bulk end points early

[Eric W. <er...@wi...>]

Dennis Muhlestein wrote:
> Eric Winsor wrote:
>   
>> I have an application where I would like to ship a 512 byte bulk in 
>> endpoint whenever the host asks for a packet.  The host will not know 
>> what size the packet is so I am planning on the host asking for 512 
>> bytes.  I just want to give the host whatever has accumulated in the 
>> EP4FIFOBUF when the host requests the in packet of 512 bytes on EP4.
>>   
>>     
> I think you'll have to tell the fx2 via a vendor command or something 
> that you'll be wanting the packet.  The fx2 can then arm the endpoint, 
> and the PC can then read the data.  There is otherwise no notice given 
> across the USB bus to whatever microprocessor that your program wants to 
> read data.  The program will just timeout on the PC side if the endpoint 
> isn't armed.
>
> Is that what you were wanting to get at?
>   
Yes.  The data comes in very intermittently and may never be 512 bytes 
in size.  I want the host to be able to get it periodically and there 
may not be anything there at times.

Eric