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

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

Dennis Muhlestein wrote:
> Eric Winsor wrote:
>   
>> 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.
>>   
>>     
> You could investigate interrupt endpoints instead of bulk maybe?  Or 
> possibly have a different vendor command that lets the PC know a 
> status.. like whether or not there is any data to get.
>   

Is there an EZ-USB register that gets set when a request happens?  Maybe 
I could trigger on that.

Eric