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PSoC™ 4 Forum Discussions

Level 3
Level 3
5 replies posted 10 questions asked 25 sign-ins

I had a discussion in the thread below.


I was able to use it as GPIO without clearing USBDEVv2_USBIO_CR1.IOMODE. However, when  USBDEVv2_CR1.REG_ENABLE=1, the internal regulator of VBUS became active and it could not be used as a 5V interface.

When the USB port is used as 5V or 3.3V GPIO output, I would like to check if the following configuration works fine.


- USBDEVv2_CR1.REG_ENABLE=0 (Default)

Is the above configuration correct when using the USB port as GPIO?


Best regards,



1 Reply
250 solutions authored 100 likes received 250 sign-ins

Hi @NXTY_Inoue 

You have mentioned that you were able to use the USB pins as GPIO without setting the IOMODE bits in the USBDEVv2_USBIO_CR1 as 0. Can you please confirm this? 

It is essential to set the IOMODE bits to 0 in order to use the USB pins as GPIOs.

The internal regulator is used to provide 3.3V to the USB D+ and D- pins in case the device is being run at 5 V (VBUS =5V). In case the device is run at 3.3V itself the internal regulator is no longer required and can remain off. 

As per your question I can understand that you want to run the USB pins as GPIO but could you also confirm if you want to use the pins at 5V or 3.3V?

Best Regards