topic It is posible implement software Flow Control (Xon/Xoff) over MKL46Z? in Kinetis Microcontrollers

It is posible implement software Flow Control (Xon/Xoff) over MKL46Z?

dhernandez-m — Sun, 01 Sep 2019 19:53:20 GMT

Hi all, Sorry if i am using bad English.

I am using UART Polled communication with the host ( Putty) over MKL46Z but i can not implement Software Flow Control (Xon/XOFF). It is posibble ? Below show the code i use to do communication task

#include "MKL46Z4.h"
#include "TxRxQueues.h"
#define UART_BUFF_SIZE (10)

char RxQBuffer[UART_BUFF_SIZE], TxQBuffer[UART_BUFF_SIZE];
struct qRecord RxQueue, TxQueue;

void UART_Init()
{
   //clock init
   init_Queue(&RxQueue, RxQBuffer, UART_BUFF_SIZE);
   init_Queue(&TxQueue, TxQBuffer, UART_BUFF_SIZE);

   SIM->SCGC4 |= SIM_SCGC4_UART2_MASK; /* Enable Clock to UART2*/
   // PTA1 -> ALT3 = UART2_RX
   // PTA2 -> ALT3 = UART2_TX
   SIM->SCGC5 |= SIM_SCGC5_PORTE_MASK; /* Enable Clock to PORTA*/
   PORTE->PCR[16] |= PORT_PCR_MUX(3UL); /* Pin PTA1 is alt2 (UART)*/
   PORTE->PCR[17] |= PORT_PCR_MUX(3UL); /* Pin PTA2 is alt2 (UART) */

UART2->C2 &= !UART_C2_TE_MASK; /* disable transmitting*/
UART2->C2 &= !UART_C2_RE_MASK; /* disable receiving */

   UART2->BDH |= UART_BDH_SBR(0);        /*set value of SBR to BDH (it is the first divider)*/
   UART2->BDL |= UART_BDL_SBR(0x185);       /*set value of SBR to BDL 26*/
   UART2->BDH &= !UART_BDH_SBNS_MASK;   /*set value of SBNS (0 - one bit, 1- two bits) */

UART2->C1 &= !UART_C1_M_MASK; /* M selects between 8 and 9 bits data MODE*/
UART2->C1 &= !UART_C1_PE_MASK; /* PE - parity enable (0 - no hardware parity)*/

//UART2->C2 |= UART2_C2_TIE_MASK; /* enable interrupt*/
//UART2->C2 |= UART2_C2_RIE_MASK;

UART2->C2 |= UART_C2_TE_MASK; /* enable transmitting*/
UART2->C2 |= UART_C2_RE_MASK; /* enable receiving */

}
void Send(uint8_t message)
{
   // Send message
       UART2->D= message;
       // Wait for transfer complete
       while(!(UART2->S1 & UART_S1_TDRE_MASK)){}
       //while(!(UART2->S1 & UART_S1_TC_MASK)){}
}

char getChar() {
char character;
int success;

   do {
       __asm("CPSID I");
       success = dequeue(&character, &RxQueue);
       __asm("CPSIE I");
   } while (!success);

return character;
}

Re: It is posible implement software Flow Control (Xon/Xoff) over MKL46Z?

jingpan — Mon, 02 Sep 2019 02:58:16 GMT

Hi Diego,

KL46 can support software flow control. Please refer to this case link https://community.nxp.com/message/511094

KL26 UART port is same to KL46. Hope this can help you.

Regards,

Jing

Re: It is posible implement software Flow Control (Xon/Xoff) over MKL46Z?

mjbcswitzerland — Mon, 02 Sep 2019 08:41:51 GMT

KL46 XON/XOFF SW and RTS/CTS HW flow control are included in the uTasker project - see the open source link below and the UART document: http://www.utasker.com/docs/uTasker/uTaskerUART.PDF

Note that XON/XOFF flow control is implemented at the driver level and not in the UART HW.

Regards

Mark

uTasker: supporting >1'000 registered Kinetis users get products faster and cheaper to market

Request Free emergency remote desk-top consulting at http://www.utasker.com/services.html

Open Source version at https://github.com/uTasker/uTasker-Kinetis