LPC5516 USB0 not being detected in ISP mode.

[asadliaquat]

Hi

 I have made board with NXP LPC5516 100 pin package. I have used USB0-FS for SP programming mode. 

I have connected PIO0_22 with VBUS, PIO0_5 with ISP boot mode.

On USB Connectivity, connected the ISP boot mode pin to ground. But there is no USB device detection on the device. 

I have also tested with LPC55S16-EVK. Also in EVK USB1 is working fine but USB0 is not being detected. 

 If someone else ever has faced this isssue kindly help me.

Regards

Asad

[diego_charles]

Hi @asadliaquat 

Thanks for reaching out.

This is an issue related to the bootROM. Basically, BootROM does not allow synchronization of the internal clock that USB0 uses. Eventougth, you may enable ISP to work on USB0, this is not a recommended practice. For details, please refer to the below post from one of my colleagues :

 [LPC55] Don’t Use ISP USB0 for firmware update

I hope this could help you

Diego