Hi,

I am using CY7C68013A-56PVXC for USB communication between PC and FPGA.I am using CTL0 and RDY0 pins for handshaking.But while sending data through the PC using .NET if we dont use 'eptbulk.reset()' function we get ambiguious results.So whats the use of this function and we really need to use it?

Thanks..

Reset() API of the endpoint member just sends a transfer to reset the state of the endpoint and unless you've written code which works with stall condition there is nothing done by that API.

Please comment on what you mean when you say ambiguous behaviour.

Regards,

Anand

Thanks for your reply..

We are receiving the image data to be printed through USB.When we use 'eptbulk.reset()' we receive the data bytes in a proper sequence and the image also get printed properly.But if we are not using the same function then the data bytes loose its sequence.

When you say data lose its sequence do you mean missing packets?? or packets in different order say like frame 4, 2, 1, 3??

Regards,

Anand

By that i mean packets in different order..it doesnt seem to be loosing packets.When not using the reset function does it overwrite the buffer?

Thanks

I don't see a logical reason behind this. Reset() API sends clear feature request to clear that particular endpoint. What does your firmware do on receiving this?

What was the intention of using this API in your application. You tried using this to solve this sequence issue or you were using it for something else and found that this solves the issue.

Regards,

Anand

We just got the step by trial and error.When we inserted 'eptbulk.reset()'  function it started working.But its affecting our speed.Actually we got the Cypress coding done by another firm,but now nobody is available who completed the coding.What this function does?

Is it possible to attach the source here. I would like to take a look.

Regards,

Anand

ya,sure.I am attaching some of the source files here.

When we use some sort of delay('for' loop) in place of 'eptbulk.reset()' it solves the problem.But in this case as well our speed concern is not solved.

Looking at your code, there is nothing special being done to handle eptbulk.Reset(). So your issue is getting solved only due to delay and has nothing to do with Reset().

Please let me know the block diagram of your design i.e. what is type of data being sent, the source of it and through which interface is it being sent.

Regards,

Anand

In that, can we check the status of endpoint in .NET? So that we can control the transmission of data.

As per your comments, The delay is also resolving the issue without the usage of Reset(). So it means the endpoint active and working fine so the status is bound to be active all the time.

Regards,

Anand

In the code AUTOOUT bit in EP2FIFOCFG and EP6FIFOCFG is '0'.Does it affects the speed since the CPU is coming in picture? Will there be any improvement if  I use AUTOOUT = '1'?

Thanks..

If you're in manual mode you've manually commit the packet everytime using CPU. This doesn't take much time but in cases where the CPU is busy and takes time to commit the packet you'll see reduction in performance.

If you'll not be modifying the packet then AUTO mode is the best way to go.

Regards,

Anand

Thanks for your reply.As you have some of our source files,could you check it and tell us what mode is used in the code.

Regards,

Saurabh

It is in manual mode as far as I can see from the attached files.

Please refer the TRM http://www.cypress.com/?docID=27095 before posting questions. It has all the necessary information.

Regards,

Anand

Thanks for your reply.I am refering TRM,but I just wanted to confirm.

Regards,

Saurabh

I am using AUTOMODE.But there is some problem with the GPIF triggering.I am attaching the code,could you please help me with it.

Hi Saurabh,

To look at GPIF kind of issue someone will have to take a closer look and understand the system before debugging. Please create a tech support case (MyAccount->MyCases) so that one of our engineers can help you with this.

Regards,

Anand

 Saurabh,

 Please check your packet size. As per USB specification maximum packet size must be 512 bytes for bulk transfer. You have kept EP2 and EP6 to be of size 1024. Keep it as 512 and try.

Also you have armed the endpoints many times. You have to do it just twice for both EP2 and EP6. Aring of an OUT Endpoint can be done either by:

1. writing dummy byte count into corresponding Endpoint's bytecount register with its skip bit (but7) set = 1.

2. by using OUTPKTEND register to skip the packets in the corresponding OUT endpoint.

OUTPKTEND register can be used only if REVCTL.0 = 1. 

Regards,

Gayathri 

can i use the cy7c63813 as a USB_SPI bridge to communicate with a CAN controller mcp2515?????????