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器件型号：MSP430FR2355 主题中讨论的其他器件： UNIFLASH
您好！
我正在尝试使用 DCO 将 MSP430FR2355设置为20MHz。 我从8MHz DCO 示例工程开始、修改了如下三行(第79、89、92行)：
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//******************************************************************************
// MSP430FR235x Demo - Configure MCLK for 8MHz sourced from DCO.
//
// Description: Default DCODIV is MCLK and SMCLK source.
// By default, FR235x select XT1 as FLL reference.
// If XT1 is present, the XIN and XOUT pin needs to configure.
// If XT1 is absent, switch to select REFO as FLL reference automatically.
// XT1 is considered to be absent in this example.
// f(DCOCLK) = 2^FLLD * (FLLN+1) * (fFLLREFCLK / n).
// FLLD = 0, FLLN =243, n=1, DIVM =1, f(DCOCLK) = 2^0 * (243+1)*32768Hz = 8MHz,
// f(DCODIV) = (243+1)*32768Hz = 8MHz,
// ACLK = default REFO ~32768Hz, SMCLK = MCLK = f(DCODIV) = 8MHz.
// Toggle LED to indicate that the program is running.
//
// MSP430FR235x
// ---------------
// /|\| |
// | | |
// --|RST |
// | P1.0 |---> LED
// | |
// | |
// | P1.1 |---> ACLK = 32768Hz
//
//
// Darren Lu
// Texas Instruments Inc.
// Oct. 2016
// Built with IAR Embedded Workbench v6.50 & Code Composer Studio v6.2
//******************************************************************************
#include <msp430.h>
void Software_Trim(); // Software Trim to get the best DCOFTRIM value
//#define MCLK_FREQ_MHZ 8 // MCLK = 8MHz
#define MCLK_FREQ_MHZ 20 // MCLK = 8MHz
int main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
__bis_SR_register(SCG0); // disable FLL
CSCTL3 |= SELREF__REFOCLK; // Set REFO as FLL reference source
// CSCTL1 = DCOFTRIMEN_1 | DCOFTRIM0 | DCOFTRIM1 | DCORSEL_3;// DCOFTRIM=3, DCO Range = 8MHz
CSCTL1 = DCOFTRIMEN_1 | DCOFTRIM0 | DCOFTRIM1 | DCORSEL_6;// DCOFTRIM=6, DCO Range = 20MHz
// CSCTL2 = FLLD_0 + 243; // DCODIV = 8MHz
CSCTL2 = FLLD_0 + 609; // DCODIV = 20MHz
__delay_cycles(3);
__bic_SR_register(SCG0); // enable FLL
Software_Trim(); // Software Trim to get the best DCOFTRIM value
CSCTL4 = SELMS__DCOCLKDIV | SELA__REFOCLK; // set default REFO(~32768Hz) as ACLK source, ACLK = 32768Hz
// default DCODIV as MCLK and SMCLK source
P1DIR |= BIT0 | BIT1; // set ACLK and LED pin as output
P1SEL1 |= BIT1; // set ACLK pin as second function
PM5CTL0 &= ~LOCKLPM5; // Disable the GPIO power-on default high-impedance mode
// to activate previously configured port settings
while(1)
{
P1OUT ^= BIT0; // Toggle P1.0 using exclusive-OR
__delay_cycles(10000000); // Delay for 10000000*(1/MCLK)=1.25s
}
}
void Software_Trim()
{
unsigned int oldDcoTap = 0xffff;
unsigned int newDcoTap = 0xffff;
unsigned int newDcoDelta = 0xffff;
unsigned int bestDcoDelta = 0xffff;
unsigned int csCtl0Copy = 0;
unsigned int csCtl1Copy = 0;
unsigned int csCtl0Read = 0;
unsigned int csCtl1Read = 0;
unsigned int dcoFreqTrim = 3;
unsigned char endLoop = 0;
do
{
CSCTL0 = 0x100; // DCO Tap = 256
do
{
CSCTL7 &= ~DCOFFG; // Clear DCO fault flag
}while (CSCTL7 & DCOFFG); // Test DCO fault flag
__delay_cycles((unsigned int)3000 * MCLK_FREQ_MHZ);// Wait FLL lock status (FLLUNLOCK) to be stable
// Suggest to wait 24 cycles of divided FLL reference clock
while((CSCTL7 & (FLLUNLOCK0 | FLLUNLOCK1)) && ((CSCTL7 & DCOFFG) == 0));
csCtl0Read = CSCTL0; // Read CSCTL0
csCtl1Read = CSCTL1; // Read CSCTL1
oldDcoTap = newDcoTap; // Record DCOTAP value of last time
newDcoTap = csCtl0Read & 0x01ff; // Get DCOTAP value of this time
dcoFreqTrim = (csCtl1Read & 0x0070)>>4;// Get DCOFTRIM value
if(newDcoTap < 256) // DCOTAP < 256
{
newDcoDelta = 256 - newDcoTap; // Delta value between DCPTAP and 256
if((oldDcoTap != 0xffff) && (oldDcoTap >= 256)) // DCOTAP cross 256
endLoop = 1; // Stop while loop
else
{
dcoFreqTrim--;
CSCTL1 = (csCtl1Read & (~DCOFTRIM)) | (dcoFreqTrim<<4);
}
}
else // DCOTAP >= 256
{
newDcoDelta = newDcoTap - 256; // Delta value between DCPTAP and 256
if(oldDcoTap < 256) // DCOTAP cross 256
endLoop = 1; // Stop while loop
else
{
dcoFreqTrim++;
CSCTL1 = (csCtl1Read & (~DCOFTRIM)) | (dcoFreqTrim<<4);
}
}
if(newDcoDelta < bestDcoDelta) // Record DCOTAP closest to 256
{
csCtl0Copy = csCtl0Read;
csCtl1Copy = csCtl1Read;
bestDcoDelta = newDcoDelta;
}
}while(endLoop == 0); // Poll until endLoop == 1
CSCTL0 = csCtl0Copy; // Reload locked DCOTAP
CSCTL1 = csCtl1Copy; // Reload locked DCOFTRIM
while(CSCTL7 & (FLLUNLOCK0 | FLLUNLOCK1)); // Poll until FLL is locked
}
不过、当我这么做时、我可以改变时钟、但我无法再对 MSP430进行编程。 我看到了 布鲁斯的以下建议:
我尝试在"Program/Memory Load"下设置"No verification"、但这可以防止我收到的错误(数据验证错误)底层程序没有被刷新。 我发现可以通过 在 uniflash 中执行批量擦除和硬复位来解决此问题、但我希望能够从 CCS 进行闪存。 我的代码中是否有什么错误 使时钟更改为20MHz 后 MSP430无法再闪存？
谢谢！
Connor
