LPC55S69: USB1 not detected when in ISP

[jean_b]

Hello,

I am trying to flash a LPC55S69 using USB1, however I am unable to make it work. In ISP, the device is not detected by Windows, and absent from the Device Manager, so using blhost to flash it naturally leads to the Error "UsbHidPeripheral() cannot open USB HID device".

The USB port itself seems to be operating correctly, as I am able to communicate with the application using it. When booting normally, the device is correctly found.

The DEFAULT_ISP_MODE is set to 0, and therefore it should be possible to flash over USB1. Currently I managed to flash using a J-Link, while I need it to be done through USB.

I have tried installing MCUxpresso to get additional drivers, without any change.

Would you know what can cause such error, and do you have any solution to this issue ?

Microcontroller: LPC55S69 1B
PC Operating System: Windows 10

Thank you in advance,

Best Regards,

Jean-Baptiste

[ZhangJennie]

Hi

I ever tested ISP USB1 with EVK board. there is no issue. I suggest you testing USB1 with external power supply.

Could you please test USB1 with EVK board withing paying attention to below points:

" When either port is used as a host, power
must be supplied to the board via the +5V power only micro B USB port. Jumper J6 is
used to connect power from a load switch to the VBUS signal of the port selected; J6
should be placed in position 1-2 for USB1 or position 2-3 for USB0. If neither USB port is
being used as a USB host this jumper is not required."

Thanks,

Jun Zhang

[jean_b]

Hello,

Thank you for your response.

I do not use the LPC55S69 EVK board, but a custom one integrating a LPC55S69JBD100 B1. And the USB1 is not working only in the Bootloader ISP mode, where the micro is supposed to be a device and not a host.

I have checked that the VBUS tension is brought to 5V, and the D+ also has a tension of 3V. So to my understanding the computer should be able to detect a device, but it does not.

[ZhangJennie]

Hi jean_b 

The part can't work in ISP USB1 mode. 

If you downnload a USB1 demo code, can it work? We need to identify the problem was caused by ISP or USB1 itself.

Thanks,

Jun Zhang

[jean_b]

Hello,

I have tried using the dev_hid_generic example for LPC55S69 with the configuration for USB1. It unfortunately does not work, while it is doing fine on a EVK board I just acquired.

It looks like it is an issue with the hardware. While comparing my board to it, the main difference I can see is the crystal, I have a 32MHz crystal while the Evaluation Board has a 16MHz one.

Can this prevent the USB HS from working from the Bootloader ?

Thank you,

Jean-Baptiste

[ZhangJennie · Accepted solution]

HI jean_b 

USB1 ISP mode reqires 16Mhz external crystal. This is must. Otherwise USB1 ISP can't work.

See statement in UM

Have a nice day,

Jun Zhang