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USB Superspeed Peripherals

ElTa_4521156
New Contributor II

Hi,
I have a question on this article:
Drive Multiple GPIO Pins Simultaneously in FX3™ - KBA212557

I need to produce 2 simultaneously output (somehow SPI in high freq) : CLK up to 28.8MHz and MOSI which should be synchronized with an input clock to FX3

I am wondering that if I use from the mentioned article, Can I get this frequency on gpio?
As in Increasing Frequency of Bit-Banged GPIO Clock in EZ-USB® FX3™ - KBA90267 , there is a limitation for frequency range.

If no, how can i get these signals from Fx3 without using GPIF II?  I have only 3 pins free on FPGA and no more for using GPIF II.

Thanks

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1 Solution
ElTa_4521156
New Contributor II

Hi,
Now, I used another way to get the desired results:Synchronized serial IN interface in GPIF .

I wanted to send a clock and get data, frame sync(SOF) and clock at the same time as output which are synchronized with the input clock. so now i had to split that input clock and use it as output as well.

Thanks

View solution in original post

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8 Replies
YashwantK_46
Moderator
Moderator

Hello,

Please refer to the following thread: GPIO Toggling frequency related

The above thread addresses a similar kind of problem.

Can you please tell your application?


Also, if you use GPIF II for this application, you still have 3 pins on FPGA that can be used with GPIF II, right?

Regards,
Yashwant

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ElTa_4521156
New Contributor II

Thanks for your answer. But the link that you sent is unauthorized for me. I couldn't open it.

I have a 32-bit data with ~0.75 MHz rate as USB input, I want to serialize it to a 1-bit data  and send it to FPGA.
Actually, I need 3 pins as clock(32*0.75 MHz) ,serial data and Frame sync going to FPGA. I receive a clock from FPGA to synchronize these pins with that.
About GPIF, you are right.  I thought that I need Control signals also. It was my mistake. But in serial communication on GPIF Interface, It seems that I couldn't produce clock at same time. As Configuring Serial OUT Interface in GPIF of FX3 – KBA228346 : DQ[15] – Serial OUT; DQ[13] – SOF signal;  DQ[12] – EOF signal.

Thanks,

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YashwantK_46
Moderator
Moderator

Hello,

Please refer to the link: Re: What is the max clock frequency that the GPIO can simulate ?

The above thread has an example firmware that you can try and see if it meets your requirements.

Please do get back with the results.

Regards,
Yashwant

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YashwantK_46
Moderator
Moderator

Hello,


Were you able to get the desired results with the firmware that was provided?

Can you share the test results that you have got?


Regards,

Yashwant

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ElTa_4521156
New Contributor II

Hi,

I used serial interface in GPIF, however it doesn't produce output clock at same time. so I had to use the same clk that i send as input.

In attached image, I send 0x66666666 (32-bit) by control center, and get serial out(yellow signal) and SOF(green signal) from pin15 and pin13.
Regard,

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YashwantK_46
Moderator
Moderator

Hi,


Can you please explain what your expectation is and what the issue you are facing currenlty?

however it doesn't produce output clock at same time. so I had to use the same clk that i send as input.

>>Could you elaborate this as well?

Regards,
Yashwant

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ElTa_4521156
New Contributor II

Hi,
Now, I used another way to get the desired results:Synchronized serial IN interface in GPIF .

I wanted to send a clock and get data, frame sync(SOF) and clock at the same time as output which are synchronized with the input clock. so now i had to split that input clock and use it as output as well.

Thanks

View solution in original post

0 Likes