MSP430FR5043: What is the Max Baud Rate on MSP430FR5043

2 Mbps is not a problem for 5xx with precise UART clock source. For setup with BRCLK from XT2 I used my offline calculator.

0121.MSP430UartCalc.rar

Hi Zrno soli,

I tried that but it didn't work.

Hi Luke Ledbetter,

I tried that but it didn't work.

it works at a minimum of 1.5Mbps. I have 2Mbps Baud Rate at UART Mode from MSP430fr5043

Part Number: MSP430FR5043

Hi,

MSP430FR5043 and MSP430F5436A Microcontroller does not Support 2Mbps Baud Rate on UART But a maximum of 1.5 Mbps is working.

I have to achieve the Baud Rate of 2Mbps on This Microcontroller.  

How to Achieve the 2Mbps Baud Rate on UART?

Thanks.

Part Number: MSP430FR5969

Hi,

I am working on a project in which MSP430FR5969 Microcontroller. I want to replace this controller

I will achieve the Baud Rate of UART is 2Mbps on MSP430FR6989 and MSP430F5436A Microcontroller. That's not Support 2Mbps Baud Rate on this controller. But a maximum of 1.5 Mbps is working.

The MSP430FR5969 controller is work on 2Mbps Baud Rate.

I will need to make these two (MSP430FR6989 and MSP430f5436A) controllers work on 2Mbps like MSP430FR5969 Controller.

What should I do?

What is your clock speed?

MSP430FR5043 SMCLK is 16MHz and  MSP430F5436A SMCLK is 6MHz.

What have you tried, and what is not working? Can you show us some not working code?

Hi Vijay, 

Can you send me the code portions for you initializing the UART and the BRCLK. 

Regards,

Luke

The data sheets include a maximum bit rate.The two parts mentioned have different maximums with one being 1 Mbps (F5436) and the other 4Mbps.

I tried 2Mbps Baud Rate on UART With Use External crystal 6MHz From MSP430F5436A Microcontroller.

C Code:

//*********************************************************** 2Mbps Baud Rate*****************************************************

#include <msp430f5436a.h>

unsigned int i;

int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT

P3SEL = 0x30;         // P3.4 = USCI_A0 TXD --- P3.5 = USCI_A0 RXD

P5SEL |= 0x0C;       // Port select XT2
P7SEL |= 0x03;       // Port select XT1

UCSCTL6 &= ~(XT1OFF + XT2OFF);                   // Set XT1 & XT2 On
UCSCTL6 |= XCAP_3;                                          // Internal load cap

                                                                              // Loop until XT1,XT2 & DCO stabilizes
do
{
UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + XT1HFOFFG + DCOFFG);
                                                                                                                      // Clear XT2,XT1,DCO fault flags
SFRIFG1 &= ~OFIFG;                                                                                  // Clear fault flags
}while (SFRIFG1&OFIFG);                                                                           // Test oscillator fault flag

UCSCTL6 &= ~XT2DRIVE0;                                                                        // Decrease XT2 Drive according to
// expected frequency
UCSCTL4 |= SELA_0 + SELS_5;                                                                // Select SMCLK, ACLK source and DCO source

UCA0CTLW0 |= 0x0081;
UCA0BRW = 3;                                            // BRCLK = SMCLK = 6MHz
UCA0MCTL |= 0x0000;
UCA0CTLW0 &= ~0x0001;

while(1)
{
UCA0TXBUF='1';
for(i=0; i < 60000; i++){}

}

}

Hi Luke,

I tried 2Mbps Baud Rate on UART With Use External crystal 16MHz From MSP430FR5043 Microcontroller.

C Code:

//************************************************* 2Mbps Baud Rate (16MHz External Oscillater)**********************************************

#include <msp430fr5043.h>

unsigned int i;

int main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop Watchdog
PM5CTL0 &= ~LOCKLPM5;

P2SEL0 &= ~(BIT0 | BIT1);
P2SEL1 |= BIT0 | BIT1; // USCI_A3 UART operation

PJSEL0 |= BIT4 | BIT5 | BIT6 | BIT7; // For XT1 and XT2

CSCTL0_H = CSKEY_H; // Unlock CS registers
CSCTL1 = DCOFSEL_6; // Set DCO to 8MHz
CSCTL2 = SELA__VLOCLK | SELS__HFXTCLK | SELM__DCOCLK;
CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1; // Set all dividers to 1
CSCTL4 |= LFXTDRIVE_3 | HFXTDRIVE_3;
CSCTL4 &= ~(LFXTOFF | HFXTOFF);

while (!(SFRIFG1 & OFIFG)); // Test oscillator fault flag

CSCTL5 &= ~(LFXTOFFG | HFXTOFFG); // Clear XT1 and XT2 fault flag
SFRIFG1 &= ~OFIFG;

CSCTL0_H = 0; // Lock CS registers

// Configure USCI_A3 for UART mode
UCA3CTLW0 = 0x0081; // Put eUSCI in reset,CLK = SMCLK
UCA3BRW = 8;
UCA3MCTLW |= 0x0000;
UCA3CTLW0 &= ~0x0001; // Initialize eUSCI

while(1)
{
UCA3TXBUF='1';

for(i=0; i < 60000; i++){}

}
}

Regards,

Vijay

Hi David,

Can You Clearly Explain Plz?

What happens when you run this code?

The first thing I see is that i should be volatile to keep it from being optimised away.

Hi Vijay,

David was pointing out the datasheet spec for UART 

MSP430FR5043 Datasheet

MSP430FR5436A Datasheet

You can't reach 2 Msps as the baud rate with the  MSP430FR5436A device is limited to 1 MHz, but you can with the MSP430FR5043. It looks like you are setting your DCO to 8 MHz instead of 16 MHz. Since your clock is 8 MHz you need UCA3BRW = 4 to get 2 Msps. With your current settings you should be getting 1 Msps.

Regards,

Luke

Transmit Char = '1';

Receiving application is docklight software. But receiving Char is not correct

Hi Luke,

I tried at 16MHz, 8MHz, 4MHz and 1MHz but didn't reach 2Mbps Baud Rate on MSP430FR5043

Did you make i volatile so that you get an actual delay? Have you checked the serial output with an oscilloscope?

__delay_cycles() usually works better than an arbitrary delay loop that the compiler could optimize away.

Waiting for TXIFG to be set before writing to TXBUF is almost always a good idea.

Default for DIVS and DIVM after a PUC is to divide by 8. I see no change to UCSCTL3 that would alter that.

For that matter, I don't see a write of CSKEY to UCSCTL0 that would unlock the clock control registers.

Hi Vijay,

I noticed that the threads were similar so I have joined them together.

Is there a reason you need to run UART at 2 Msps? Looking at the error rate in our table of recommended settings for the MSP430FR5043

The error rate is close to linear so if you need ~4x the 460800 speed you're going to run close to an error of ~5.7% at 2Msps. (Check out this TI Precision Labs video on UART Error)

Is it possible to use SPI in your use case instead?

Regards,

Luke

Hi Luke.

Our requirement is specific to UART only, we want to send the data to an external application.

What is the baud rate you are seeing with the settings that "should" give 2 Msps?

Also is this a custom board and not a TI EVM?

Regards,

Luke

Hi Luke, 

We will get 2Mbps BaudRate in Uart From MSP430FR5943 Board

Thanks For Help

Luke