LPC4088 USB: how do I switch between interfaces within one configuration

[NEIL4]

Hello,

I am using LPC4088, I have configured interface  USB in HMI(PORTSEL 0) and MSD (PORTSEL 1) one at a time  individually working fine. In runtime when I Deint (USB-MSD) and Init (USB-HMI) vice versa I am getting continuous interrupt. I have some general questions.

1. Can both interface work simultaneously, how to configure them?

2. In runtime when I Deint (USB-MSD) and Init (USB-HMI) vice versa I am getting continuous interrupt, why?

3. How many max interfaces should be configured?

4. Difference between logical and physical endpoint? 

5. General guidelines for USB-MSD configuration, selection of endpoint type, size etc.

6. General guidelines for USB-HMI configuration, selection of endpoint type, size etc.

7. What is Double buffer w.r.t. endpoint and its use cases?

Earlier I did bare metal embedded programming, How to understand USB stack in depth?

Thank you.

[EdwinHz]

Hi @NEIL4,

I’m afraid you are not able to have the same USB module configured with two different ports at the same time. This is most likely why your USB interruptions are getting mistakes when you try both configurations. My best recommendation would be to try the USB examples that we provide on the LPCOpen libraries to get a better understanding of the configuration of the USB modules.

BR,

Edwin.

[NEIL4 · Accepted solution]

Thank you, EdwinHz.