Clean FX3 on custom board: VID=0x0000 and Device Descriptor Request Failed

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LeGa_3963206
Level 4
Level 4
50 replies posted 25 replies posted 10 replies posted

Hello,

We are developing custom board with FX3. We took as example SuperSpeed Starter Kit schematics

In both modes I2C boot to USB fallback and USB boot devices enumeration occures: VID=0x000, PID=0x0002.

Currently our I2C EEPROM is empty.

So far we checked:

     - AN70707

     - AN76405

PMODE[2:0] checked:

     - Z11

     - 1ZZ

     - Z1Z

Also external crystal is OK - 19.2MHz

All VDD, VIO, etc.. also good

Is there anything else that should be checked?

Thanks

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1 Solution

190501_232058.bmp

Refer to the screenshot above. Ch1 is D+ and Ch3 is D-.

Have you checked another FX3 chip? Is this FX3 chip broken?

View solution in original post

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12 Replies
cycy_1740621
Level 4
Level 4
First comment on KBA 10 solutions authored 25 replies posted

Could you share the schematic the part of USB interface?

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Update:

I was able to load my FW to FX3 through JTAG and burn I2C EEPROM.

In that case it boots OK.

Is there any chance that FX3 comes from factory without Cypress bootloader as it stated in TRM?

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Hemanth
Moderator
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Moderator
First like given First question asked 750 replies posted

Hi,

- I hope USB precision resistors have 1% tolerance

- Please share the entire schematic.

- FX3 coming from factory will come with bootloader.

Regards,

Hemanth

Hemanth
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Hi, Hemanth

1) Yes, all resistors are 1%.

2) I'm attaching relevant schematics. But just for you to know it's the same as SuperSpeed Dev kit.

Thanks,

Leonid

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Hi,

Is there any suggestions so far?

Thanks

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Hi LeGa,

1. Could you share the screenshot of device manager? Does FX3 show as an unknown device?

2. If you have an USB analyzer, please share the USB trace file.

3.You could try to probe USB D+/D- pin on USB connector to check the waveform when the system boots.

I suggest you to check the USB2.0 signals becasue it's simple for users. I could show you a correct waveform later.

4. Please ensure you have installed the corresponding driver package.

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Hi LeGa,

1. Could you share the screenshot of device manager? Does FX3 show as an unknown device?

2. If you have an USB analyzer, please share the USB trace file.

3.You could try to probe USB D+/D- pin on USB connector to check the waveform when the system boots.

I suggest you to check the USB2.0 signals becasue it's simple for users. I could show you a correct waveform later.

4. Please ensure you have installed the corresponding driver package.

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Hi,

1. Here it is:

pastedImage_0.png

2. I have only sowtware USB trace program, but It's impossible to use it because device is not recognized

3. I can try. But what am I supposed to see? D+/D- are differential pair which can't be adequately seen on scope.

4. Irrelevant - device provides wrong VID/PID

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190501_232058.bmp

Refer to the screenshot above. Ch1 is D+ and Ch3 is D-.

Have you checked another FX3 chip? Is this FX3 chip broken?

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Remember to connect your board to PC with a USB2.0 cable.

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Hi,

I tried to get the same image on scope while found that D+ and D- are swapped on our schematics.

Thanks a lot!

Leonid

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