Hello,

I'm confused about FX3's boot mode.
As I understand from FX3 Programmers Manual page 42, FX3's firmware and VID/PID/DID can be change over USB cable without using an eeprom thorough renumeration process.

If I understand right, then why an eeprom is needed for a host connected (via USB cable) FX3 system?

What can't be done with usb boot mode in USB connected FX3 system?

Regards,

Ali

Hi Ali,

check the application note describing FX3's boot via USB: http://www.cypress.com/?rID=56486

It contains the answers to your questions!

Regards,

Rob

Hi Rob,

When I reread the application note, "USB with VID/PID Options" title got my attention. As I understand from the title, there is a three source to change VID/PID that are I2C eeprom, SPI eeprom and efuse. The efuse seems like custom manufacturing which is not a preferred way.

Therefore without using an eeprom or efuse process, VID/PID can't be changed. Am I right?

Regards,
Ali

The VID/PID option being spoken about is to change just the VID/PID of the device (no firmware).

With USB boot as well you'll be able to change VID/PID i.e. by downloading entire firmware and have firmware handle the descriptor requests. Here is the problem with using the default VID/PID (i.e. using no EEPROM), there is the script download method using which cyusb.sys will download firmware to device bound to it.

If 2 different designs use the default VID/PID and script download method then when they're used in the same PC there is a possibility of cross-downloading for firmware. So designs which want to reduce EEPROM size use a small EEPROM just for VID/PID and then this VID/PID is bound to cyusb.sys plus a script file. The script file will have the firmware to be downloaded it will download that and renumerate.

Regards,

Anand

Rob and Anand,

Thanks, I clearly understand the process now.

Regards,
Ali

Hello：

        Now I am learning usb3.0 and have draw a usb3.0+fpga board.I begin debug,but I encounter a problem.I set PMODE[2:0]=F1F,but I get  PMOD[2:0]=111,why？And I  find  unknow drive(VID=0000,PID=0000),but sometimes I find Cypress USB BootLoader,why?

 Did you get a chance to look at this application note:

http://www.cypress.com/?rID=53203

Regards,

sai krishna

hello:

          I cannot still understand it! Ihope to get specific instruction.

regards

Alian

 Alian,

Could you please share your board schematics with me. 

Did you get them reviewed by any Cypress engineer.

Thanks,

sai krishna.