topic Re: Does KEA128 support DMA, I need a UART DMA sample in Kinetis Design Studio

Does KEA128 support DMA, I need a UART DMA sample

vaughn — Mon, 28 May 2018 00:57:35 GMT

There's no DMA description on KEA128 RM, is this mean no DMA support on KEA128?

If it support DMA, do anybody give an UART DMA transmit/receive sample? I want to implement a receive with an idle interrupt, transmit with any length.

Re: Does KEA128 support DMA, I need a UART DMA sample

Alice_Yang — Mon, 28 May 2018 06:51:37 GMT

Hello ,

Yes, it doesn't support DMA .

Hope it helps

Have a great day,
TIC

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Re: Does KEA128 support DMA, I need a UART DMA sample

vaughn — Mon, 28 May 2018 12:22:48 GMT

Thanks, Yang.

I want to minimize the RX/TX interrupt number, some thing just like DMA do:

1), when TX data finished, an interrupt to notify me that, it finished, then i could update user defined TX finished status, and

2), when RX line is idle, an interrupt to notify me that, there's no more data.

I do not know is this robust?

The following file is KEA128's UART driver and Events.c, i want to optimize it if possible.

Re: Does KEA128 support DMA, I need a UART DMA sample

Alice_Yang — Tue, 29 May 2018 07:32:39 GMT

Hi xiaofeng,

Do you meaning do not use interrrupt . Yes, you can also use polling mode ,

check the TX/RX flag status . There is also the polling demo under Typical Usage:

Hope it helps

Have a great day,
TIC

Re: Does KEA128 support DMA, I need a UART DMA sample

vaughn — Tue, 29 May 2018 08:37:13 GMT

Hi Yang, I think it's not practical which PE does is that OnBlockReceived event require we have to know that the number to be receive. And the polling method may lost frame if receiving loop slow.

What I need is that:

1, if block sending finished, there's interrupt to notify me, then I can set transmit finish flag(or call it transmit idle).

2, when receiving, I want to avoid RX interrupt on each receive byte in interrupt mode which is low efficient, OR receiving byte maybe lost in polling mode.

Thanks!

Re: Does KEA128 support DMA, I need a UART DMA sample

vaughn — Tue, 29 May 2018 17:48:27 GMT

And the other reason I need RX idle interrupt is that, there's a senari is that, the receiving data length unknown.

Re: Does KEA128 support DMA, I need a UART DMA sample

Alice_Yang — Wed, 30 May 2018 03:30:35 GMT

Hi ,

Sorry , I'm afraid I don't know what's your problem now .

I recommend you first write your code , then debug , check whether it can work well

as your requirement . Then you can show the detail question when there is problem .

Alice

Re: Does KEA128 support DMA, I need a UART DMA sample

vaughn — Wed, 30 May 2018 05:02:49 GMT

Thank you Yang.