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MSP430单片机的时钟设置感觉很麻烦，我碰到一个问题，使用DCO时钟6M，不知道怎么弄大家看看：
#include <msp430x12x2.h>
#define DELTA 1024 // target DCO = DELTA*(4096) = 6M
//#define DELTA 256 // target DCO = DELTA*(4096) = 1M
void Set_DCO (void);
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
Set_DCO(); // Set DCO
while (1);
}
//------------------------------------------------------------------------------
void Set_DCO (void) // Set DCO to selected frequency
//------------------------------------------------------------------------------
{
unsigned int Compare, Oldcapture = 0;
BCSCTL1 |= DIVA_3; // ACLK= LFXT1CLK/8
CCTL2 = CM_1 + CCIS_1 + CAP; // CAP, ACLK
TACTL = TASSEL_2 + MC_2 + TACLR; // SMCLK, cont-mode, clear
while (1)
{
while (!(CCIFG & CCTL2)); // Wait until capture occured
CCTL2 &= ~CCIFG; // Capture occured, clear flag
Compare = CCR2; // Get current captured SMCLK
Compare = Compare - Oldcapture; // SMCLK difference
Oldcapture = CCR2; // Save current captured SMCLK
if (DELTA == Compare) break; // If equal, leave "while(1)"
else if (DELTA < Compare) // DCO is too fast, slow it down
{
DCOCTL--;
if (DCOCTL == 0xFF)
{
if (!(BCSCTL1 == (XT2OFF + DIVA_3)))
BCSCTL1--; // Did DCO roll under?, Sel lower RSEL
}
}
else
{
DCOCTL++;
if (DCOCTL == 0x00)
{
if (!(BCSCTL1 == (XT2OFF + DIVA_3 + 0x07)))
BCSCTL1++; // Did DCO roll over? Sel higher RSEL
}
}
}
CCTL2 = 0; // Stop CCR2
TACTL = 0; // Stop Timer_A
}
就是无法初始化成功，求助。。。。。。。给个例子参考也好 |
阿莫论坛20周年了！感谢大家的支持与爱护！！
曾经有一段真挚的爱情摆在我的面前，我没有珍惜，现在想起来，还好我没有珍惜……
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发表于 2012-10-8 20:46:58