FX 3 USB boot fault

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teiic_293761
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Welcome!

Hi,

We made a wrong terminal connection of FX 3 and connected the RESET # terminal directly to the INT # terminal.

As a result, I encountered a phenomenon that the USB BOOT operation does not work.

The SPI boot operation works without problems.

Where is the cause of the USB boot operation not functioning?

What is wrong with directly connecting the RESET # pin to the INT # pin?

Those who have knowledge please give us information.

Best regards,

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1 Solution

Hello,

I was able to see the similar scenario using the Cypress FX3 SuperSpeed Explorer Kit. This is a behavior of the FX3 boot-loader that resides in the internal ROM and hence cannot be modified. So, kindly, modify the hardware to remove the connection of INT# pin to RESET# pin.

Best regards,

Srinath S

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6 Replies
SrinathS_16
Moderator
Moderator
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1000 replies posted 750 replies posted 500 replies posted

Hello,

- Please let us know what is the PMODE line setting that you are using.

- It is recommended to maintain a minimum reset pulse width of 1ms. Kindly, check if this is satisfied in your condition.

- Please share the schematic of your design around the RESET# pin.

Best regards,

Srinath S

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Hello, Srinath S-San

Thank you for reply.

(1)PMODE

We use PMODE[2:0] line

Z11 USB Boot

0Z1 SPI Boot

set above state with external switch's setting..

(2)RESET# condition

At Main power on , No reset pulse is applied

When RESET# and INT# are disconnected, USB boot was possible even without reset pulse with our board.

(3)Schematic

Pls refer to attached PNG

FX3_Circuit.png

Regards,

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Hello,

- Can you please probe the RESET# pin on both the boot modes and share the same?

- Also, let me know if the SPI boot mode works fine all the time.

Best regards,

Srinath S

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Hello, Srinath-San

(1)INT# and RESET# pin Probe result

Approximately 3.5 msec later from power on, the INT # pin outputs a low level signal. This works only in USB boot mode.

In the SPI boot mode power up sequence, the INT # output is never changed.

Therefore, when INT # -RESET # is directly connected, I understand that the RESET # input will be applied at power on, and the USB boot operation will be canceled.

Is it the specification that INT # outputs during USB boot operation?

Regards,

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Hello,

I was able to see the similar scenario using the Cypress FX3 SuperSpeed Explorer Kit. This is a behavior of the FX3 boot-loader that resides in the internal ROM and hence cannot be modified. So, kindly, modify the hardware to remove the connection of INT# pin to RESET# pin.

Best regards,

Srinath S

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Hello  Srinath-San,

Thank you for response.

We will modify hardware connection.

Best regards,

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