我想使用MSP430F4270加一个32.768HZ的低频晶振 但是找不到管脚接口。我查了F169系列的都有。 如果没有我怎么让看门狗的复位时间变长,比如变为5S
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我想使用MSP430F4270加一个32.768HZ的低频晶振 但是找不到管脚接口。我查了F169系列的都有。 如果没有我怎么让看门狗的复位时间变长,比如变为5S
qiang xue 说:看到选择模式了,配置倍频的寄存器是哪一些 能不能给一个例程。
//****************************************************************************** // MSP430x42x0 Demo - FLL+, Runs Internal DCO at 8MHz // // Description: This program demonstrates setting the internal DCO to run at // 8MHz with auto-calibration by the FLL+. // ACLK = LFXT1 = 32768, MCLK = SMCLK = DCOCLK = (121+1) x 2 x ACLK = 7995392Hz // //* An external watch crystal between XIN & XOUT is required for ACLK *// // // MSP430F4270 // ----------------- // /|\| XIN|- // | | | 32kHz // --|RST XOUT|- // | | // | P1.1/MCLK|--> MCLK = 8Mhz // | | // | P1.5/ACLK|--> ACLK = 32kHz // | | // // L. Westlund / S. Karthikeyan // Texas Instruments Inc. // June 2005 // Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.30A //***************************************************************************** #include <msp430.h> int main(void) { WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer SCFI0 |= FN_3; // Set DCO operating range SCFQCTL = 121; // (121+1) x 32768 x 2 = 7.99 Mhz FLL_CTL0 = DCOPLUS + XCAP14PF; // DCO+ set so freq = xtal x D x N+1 P1DIR = 0x22; // P1.1,5 to output direction P1SEL = 0x22; // P1.1,5 to output MCLK & ACLK while(1); // Loop in place }
WDTCTL = WDTPW + WDTHOLD;
// Stop watchdog timer
SCFI0 |= FN_3;
// Set DCO operating range
SCFQCTL = 121;
// (121+1) x 32768 x 2 = 7.99 Mhz
FLL_CTL0 = DCOPLUS + XCAP14PF;
// DCO+ set so freq = xtal x D x N+1
qiang xue 说:
WDTCTL = WDTPW + WDTHOLD;
// Stop watchdog timer
SCFI0 |= FN_3;
// Set DCO operating range
SCFQCTL = 121;
// (121+1) x 32768 x 2 = 7.99 Mhz
FLL_CTL0 = DCOPLUS + XCAP14PF;
// DCO+ set so freq = xtal x D x N+1
也就是说只需要配置前面几条语句就可以使用32.768KHz倍频到8M频率了 是不是这个意思
是的