topic Re: UART using DMA on FRDM-KL25Z128 in Kinetis Microcontrollers

UART using DMA on FRDM-KL25Z128

yadhukrishnanvm — Sat, 07 Jan 2017 13:41:43 GMT

Hi,

I have completed uart transmission on FRDM-KL25Z using DMAChannel_LDD and Init_UART components in code warrier.I am using UART0 of the kl25z, the pins are setup as PTA1 and PTA2 which are connect to OpenSDA port. I got the correct output using the below code.

/* Including needed modules to compile this module/procedure */

#include "Cpu.h"
#include "Events.h"
#include "DMACH1.h"
#include "DMA1.h"
#include "UART0.h"
/* Including shared modules, which are used for whole project */
#include "PE_Types.h"
#include "PE_Error.h"
#include "PE_Const.h"
#include "IO_Map.h"

void StartApp(void);

uint8_t dmaSrc[]="\fHello Yadu Bro\r\n ";/* array used as source for DMA to set uart */

void StartApp(void) {

DMA_PDD_SetSourceAddress(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, (uint32_t)&dmaSrc[0]); /* set destination address */
DMA_PDD_SetSourceAddressModulo(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, DMA_PDD_CIRCULAR_BUFFER_16_BYTES); /* circular buffer with 32 bytes */
DMA_PDD_EnableSourceAddressIncrement(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, PDD_ENABLE); /* source address will be incremented by transfer size */
DMA_PDD_SetSourceDataTransferSize(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, DMA_PDD_8_BIT); /* Transfer from source size is 16bit */

DMA_PDD_SetDestinationAddress(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, (uint32_t)&UART0_D); /* set destination address */
DMA_PDD_SetDestinationAddressModulo(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, DMA_PDD_CIRCULAR_BUFFER_DISABLED); /* no circular buffer */
DMA_PDD_EnableDestinationAddressIncrement(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, PDD_DISABLE); /* no auto-increment for destination address */
DMA_PDD_SetDestinationDataTransferSize(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, DMA_PDD_8_BIT); /* Transfer to destination size is 16bit */

DMA_PDD_SetByteCount(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, sizeof(dmaSrc)); /* set number of bytes to transfer */
DMA_PDD_EnableTransferCompleteInterrupt(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, PDD_ENABLE); /* request interrupt at the end of the DMA transfer to set new byte count */
DMA_PDD_EnablePeripheralRequest(DMA_BASE_PTR, DMA_PDD_CHANNEL_0, PDD_ENABLE); /* enable request from peripheral */

Cpu_EnableInt(); /* enable interrupts */

for(;;) {
/* just wait here, DMA will do the work.... */
}
}

int main(void)

{

PE_low_level_init();

StartApp();

#ifdef PEX_RTOS_START
PEX_RTOS_START();
#endif

for(;;){}
}

Now I want to receive the data through the receiver when I type letters in keyboard. What changes I have to made on above code to receive the characters. Please help!

Re: UART using DMA on FRDM-KL25Z128

kerryzhou — Tue, 10 Jan 2017 05:35:31 GMT

Hi Yadhukrishnan V M,

About the UART DMA receive code in the KL25, please refer to my attached code.

This code is using the DMA put the uart received data to the SRAM.

Actually, you just need to configure the DMA source address as UART0_D, the destination address as the SRAM, and destination address will be incremented after each transfer.

Wish it helps you!

Have a great day,
Kerry

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Re: UART using DMA on FRDM-KL25Z128

yadhukrishnanvm — Tue, 10 Jan 2017 07:01:40 GMT

Thanks for the help. Do you have spi code using DMAChannel_LDD component?

Re: UART using DMA on FRDM-KL25Z128

kerryzhou — Tue, 10 Jan 2017 07:10:26 GMT

No, I don't have it, I just have the bare bone code which I already give you.

You can refer to my code and write it in your project.

Have a great day,
Kerry

Re: UART using DMA on FRDM-KL25Z128

yadhukrishnanvm — Tue, 10 Jan 2017 07:12:33 GMT

Its okay..anyway thanks...