NXP QN9080C: UART and VCOM

[sapna_skinner]

Hi,

I am working with QN908x SoC. I need to enable both VCOM and UART as two separate channels of communication. I am trying to do this by setting up two tasks: 1) For USB which spawn VCOM and 2) For UART. I have noticed throughout the example code that VCOM uses UART0 as base and pins pin16, 17, as USART i/o. My questions are:

1) Is it possible for UART0 FIFOs and pin16, 17 to service both threads/tasks?

2) Where can I setup a particular interrupt to a particular pin input? For example I see in the user guide that Flexcomm0 generates IP_FC0, So am I correct in assuming that this interrupt is generated when pin 17 Rxd fills UART0's FIFO? I also see that pin 4 and 5 can also be used for TxD and RxD, how can I map these pins to fill UART0's FIFOs instead of pins 16,17 and similarly then remap pins 16,17 to UART1's FIFOs?

Any advice is welcome

Thanks,

Sapna

[stephanie_m]

Hello,

Just to confirm , are you looking to have two different functionalities in the same pins  ?

About the FIFO questions, what exactlydo you mean by FIFO setup for the pins ? do you mean the TX and RX ? are you looking forward to use the DMA ?

Have you checked the qn908xcdk_driver_examples_usart_dma_transfer example?

This it's included in the driver examples located in the SDK.

regards,

Estephania

[sapna_skinner]

Yes, I am looking to service both vcom and UART tasks (separate threads) from the same UART0 pins. By FIFO I mean UART0 has a fixed base address where it has its buffers for Tx and Rx FIFOs.

I do not need dma access, simply two tasks being able to send and receive data packets with the same UART pins and registers. I was wondering if that’s possible and what that setup might look like.

Thank you,

Sapna

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[stephanie_m]

Hello,

I believe there is a confusion here, the MCU does not have a VCOM function configuration in the pins.

What you might be seeing in the development kit it's that the QN908x sends a serial message to the LPC, which it's on board, and the LPC it's the one in charge of creating the virtual com with the computer, in both cases you will have to set the UART configuration with the flexcomm module,

Nonetheless, you will need to consider that if you have the same lines connected to several components you will receive all the messages to the connections you made.

If you have more questions, let me know.

Regards,
Estephania