MSP430F5419A UART1使用XT2 問題

各位先進好

F5419A 有4個UART PORT.

使用XT2 (8MHZ) 做為CLOCK SOURCE.

單獨使用 UART0.UART2,UART3通訊115200bps 都正常

一旦啟用UART1, 全部UART失效.

且 P11.2 輸出從8MHZ 變1MHZ?

請問  先進  是否有建議 ??000_UART1_FAIL_XT2.pdf200_UART0123_A.c??

Susan Yang：

很抱歉，我找了一下这边的板子都是没有XT2的，所以无法测试您的程序

但是我看了您的代码，并没有发现问题

tojijn Twu

一旦啟用UART1, 全部UART失效.

且 P11.2 輸出從8MHZ 變1MHZ?

请问您在单独测试UART1的时候，程序是会卡在哪里？UART寄存器哪里异常？

tojijn Twu：

回复 Susan Yang:

>一旦啟用UART1 .則SMCLK 從8MHZ 變成原本之1MHZ.. 就這樣.

>所以我的對策是

  UART 全部使用內建DCO=1.034MHZ. 115200bps.  四個channel 都OK可用

>如果想要更精準ˋ之CRYSTAL  XT2. 則必須捨棄 UART1

   以上是 問題與解法   謝謝

Susan Yang：

回复 tojijn Twu:

谢谢您的反馈，但XT2应该是可以用与UART1的。我稍后会再次确认一下

tojijn Twu：

回复 Susan Yang:

我的晶片是文曄科技代理原廠貨

而且連續二片出現相同狀況.

Susan Yang：

回复 tojijn Twu:

it would be necessary to understand in more detail on what specific instruction execution the clock changes from 8MHz to 1MHz SMCLK. Basically it sould be very easy to figure this out by stepping through the code.

In addition, what does it mean the UART have been disabled? From control register settings? I assume not.

I seems also the reference used for the DCO is the REFO oscillator, and thus as well for the SMCLK. The SMCLK is again used for the UART communication. Keep in mind the REFO is usually not accurate enough for UART communication, as its maximum tolerance is violating the UART accuracy.

我就您的问题在英文论坛上由相关询问，您可以参考或补充详细信息

e2e.ti.com/…/3392860

Susan Yang：

回复 tojijn Twu:

请问您现在情况怎么样了？

我在MSP430F5529 LAUNCHPAD上测试了一下，使用XT2 4Mhz/UART1是可以正常使用的

代码如下

/* --COPYRIGHT--,BSD_EX* Copyright (c) 2012, Texas Instruments Incorporated* All rights reserved.** Redistribution and use in source and binary forms, with or without* modification, are permitted provided that the following conditions* are met:** *Redistributions of source code must retain the above copyright*notice, this list of conditions and the following disclaimer.** *Redistributions in binary form must reproduce the above copyright*notice, this list of conditions and the following disclaimer in the*documentation and/or other materials provided with the distribution.** *Neither the name of Texas Instruments Incorporated nor the names of*its contributors may be used to endorse or promote products derived*from this software without specific prior written permission.** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.**********************************************************************************MSP430 CODE EXAMPLE DISCLAIMER** MSP430 code examples are self-contained low-level programs that typically* demonstrate a single peripheral function or device feature in a highly* concise manner. For this the code may rely on the device's power-on default* register values and settings such as the clock configuration and care must* be taken when combining code from several examples to avoid potential side* effects. Also see www.ti.com/grace for a GUI- and www.ti.com/msp430ware* for an API functional library-approach to peripheral configuration.** --/COPYRIGHT--*/
//******************************************************************************
//MSP430F552x Demo - XT2 sources MCLK & SMCLK
//
//Description: This program demonstrates using XT2 to source MCLK. XT1 is not
//connected in this case.
//
//By default, LFXT1 is requested by the following modules:
//- FLL
//- ACLK
//If LFXT1 is NOT used and if the user does not change the source modules,
//it causes the XT1xxOFIFG flag to be set because it is constantly looking
//for LFXT1. OFIFG, global oscillator fault flag, will always be set if LFXT1
//is set. Hence, it is important to ensure LFXT1 is no longer being sourced
//if LFXT1 is NOT used.
//MCLK = XT2
//
//MSP430F552x
//-----------------
///|\ ||
//|||
//---|RST|
//|XT2IN|-
//|| HF XTAL (455kHz - 16MHz)
//|XT2OUT|-
//||
//|P7.7|--> MCLK = XT2
//|P2.2|--> SMCLK = XT2
//
//Bhargavi Nisarga
//Texas Instruments Inc.
//April 2009
//Built with CCSv4 and IAR Embedded Workbench Version: 4.21
//******************************************************************************#include <msp430.h>int main(void)
{WDTCTL = WDTPW + WDTHOLD;// Stop watchdog timerP2DIR |= BIT2;// SMCLK set out to pinsP2SEL |= BIT2;P7DIR |= BIT7;// MCLK set out to pinsP7SEL |= BIT7;P5SEL |= BIT2+BIT3;// Port select XT2UCSCTL6 &= ~XT2OFF;// Enable XT2UCSCTL3 |= SELREF_2;// FLLref = REFO// Since LFXT1 is not used,// sourcing FLL with LFXT1 can cause// XT1OFFG flag to setUCSCTL4 |= SELA_2;// ACLK=REFO,SMCLK=DCO,MCLK=DCO// Loop until XT1,XT2 & DCO stabilizes - in this case loop until XT2 settlesdo{UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);// Clear XT2,XT1,DCO fault flagsSFRIFG1 &= ~OFIFG;// Clear fault flags}while (SFRIFG1&OFIFG);// Test oscillator fault flagUCSCTL6 &= ~XT2DRIVE0;// Decrease XT2 Drive according to// expected frequencyUCSCTL4 |= SELS_5 + SELM_5;// SMCLK=MCLK=XT2//UARTP4SEL |= BIT4+BIT5;// P4.5 = RXD, P4.4=TXDUCA1CTL1 |= UCSWRST;// **Put state machine in reset**UCA1CTL1 |= UCSSEL_2;// SMCLKUCA1BR0 = 34;// 4MHz 115200 (see User's Guide)UCA1BR1 = 0;// 4MHz 115200UCA1MCTL |= UCBRS_1 + UCBRF_0;// Modulation UCBRSx=1, UCBRFx=0UCA1CTL1 &= ~UCSWRST;// **Initialize USCI state machine**UCA1IE |= UCRXIE;// Enable USCI_A0 RX interrupt__bis_SR_register(LPM0_bits + GIE);// Enter LPM0, interrupts enabled//while(1);// Loop in place
}// Echo back RXed character, confirm TX buffer is ready first
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=USCI_A1_VECTOR
__interrupt void USCI_A1_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_A1_VECTOR))) USCI_A1_ISR (void)
#else
#error Compiler not supported!
#endif
{
switch(__even_in_range(UCA1IV,4))
{
case 0:break; // Vector 0 - no interrupt
case 2: // Vector 2 - RXIFG
while (!(UCA1IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
UCA1TXBUF = UCA1RXBUF; // TX -> RXed character
break;
case 4:break; // Vector 4 - TXIFG
default: break;
}
}

tojijn Twu：

回复 Susan Yang:

真的非常感謝您.

UART1還是無法使用XT2(8MHz)

如果未來有新發現.再來報告.再一次致謝

Susan Yang：

回复 tojijn Twu:

好的，期待您的反馈