topic IMXRT1024 LPUART TransferNonBlocking vs eDMA Interrupt Amount Comparision in i.MX RT Crossover MCUs

IMXRT1024 LPUART TransferNonBlocking vs eDMA Interrupt Amount Comparision

Lukas_Frank — Tue, 02 Nov 2021 10:22:51 GMT

Hi Dear Authorized,

I am on the way to establish my software architecture to use LPUART in my project. I just want to select better performance based way. I am debugging into the "lpuart_interrupt_transfer.c " default SDK example. Aim of this debug is monitoring how many interrupt occurs when I transmit or receive my datas. I added below codes to default SDK example of "lpuart_interrupt_transfer.c" :

#define DEMO_LPUART_IRQn LPUART1_IRQn #define DEMO_LPUART_IRQHandler LPUART1_IRQHandler uint32_t IRQ_Count = 0; void DEMO_LPUART_IRQHandler(void) { IRQ_Count++; SDK_ISR_EXIT_BARRIER; }

My trial is monitor how many interrupt occur while sending default data string below:

uint8_t g_tipString[] = "Lpuart interrupt example\r\nBoard receives 8 characters then sends them out\r\nNow please input:\r\n";

For example I put breakpoint to below line :

LPUART_TransferSendNonBlocking(DEMO_LPUART, &g_lpuartHandle, &xfer);

After above line works I am looking for how many interrupt occured for this process. But code stucking in IRQ_Handler.

I know ECHO SIZE is 8. But I just want to learn, how many interrupt is occuring while TransferNonBlocking operations. Could you please help me?

Q1:We have 4 words of RX TX FIFO buffer. Will my code exposed to interrupt for every 4 words in TransferNonBlocking usage ?

Q2:Which one of methods(TransferNonBlocking vs eDMA) do you suggest to use?

Thanks and Regards.

Re: IMXRT1024 LPUART TransferNonBlocking vs eDMA Interrupt Amount Comparision

FelipeGarcia — Tue, 09 Nov 2021 18:47:43 GMT

Hi Lukas,

Your implementation is not correct because you are declaring IRQ handler twice. In lpuart_interrupt_transfer example IRQ is already in use so you should not add the code you included. If you want to count how many times it is entering the interrupt you could add the counter in the LPUART_TransferHandleIRQ in fsl_lpuart.c

Have a great day,

Felipe

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Re: IMXRT1024 LPUART TransferNonBlocking vs eDMA Interrupt Amount Comparision

Lukas_Frank — Wed, 10 Nov 2021 08:22:24 GMT

Thank you Dear @FelipeGarcia . I expect IRQ handler would be in main code side and didn't see IRQ Handler in fsl_lpuart.c. I will be focus you recommendation.

Best Regards.