fx3 showing "Unknown device" when connected to PC.

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rasa_3547096
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I have made a custom board with fx3 which communicates data through FPGA to PC. but, it is showing "Unknown device" when connected to PC.

Where as when EVM kit is connected, it is working just fine.

Following configuration is used in the board:

1. Synchronous Slave FIFO Interface with  32-bit Data Bus.

2. 38.4-MHz input CLK

3. Interface frequencies up to 96.8Mhz
4. PMode [Z11]

As of now, while comparing the schematic, I have found that pin D1 [DQ31] is interchanged with E4 [I2S_clk], though I am not using I2S mode and all other pins i.e D2,D3 and C4 are not connected.

I need to know, what could be the possible reasons for the device not getting detected and what are the repercurssions of the two interchanged pins.

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abhinavg_21
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50 likes received 25 likes received 10 likes received

Hi Rajagopalan,

There are some hardware design guidelines provided by cypress in following application note:

http://www.cypress.com/documentation/application-notes/an70707-ez-usb-fx3-fx3s-hardware-design-guide... .

If your device is not enumerating even with Bootloader then there is some problem in the hardware.

Please check your schematic according to the above mentioned AN 70707.

Thanks & regards

Abhinav

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abhinavg_21
Moderator
Moderator
Moderator
50 likes received 25 likes received 10 likes received

Hi Rajagopalan,

There are some hardware design guidelines provided by cypress in following application note:

http://www.cypress.com/documentation/application-notes/an70707-ez-usb-fx3-fx3s-hardware-design-guide... .

If your device is not enumerating even with Bootloader then there is some problem in the hardware.

Please check your schematic according to the above mentioned AN 70707.

Thanks & regards

Abhinav

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