?? msp430x261x_hfxt2.c
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//******************************************************************************
// MSP430x26x Demo - Basic Clock, MCLK Configured to Operate from XT2 HF XTAL
//
// Description: Proper selection of an external HF XTAL for MCLK is shown
// using HF XT2 OSC. OFIFG is polled until the HF XTAL is stable; only then is
// MCLK sourced by XT2. MCLK is buffered on P5.4 and MCLK/10 is on P1.1 driven
// by a software loop taking exactly 10 CPU cycles.
// ACLK = MCLK = LFXT1 = HF XTAL, SMCLK = default DCO ~1.045MHz
// //* XT2 HF XTAL NOT INSTALLED ON FET *//
// //* Min Vcc required varies with MCLK frequency - refer to datasheet *//
//
// MSP430F261x/241x
// -----------------
// /|\| XIN|-
// | | |
// --|RST XOUT|-
// | |
// | |
// | XT2IN|-
// | | HF XTAL (400kHz - 16MHz)
// | XT2OUT|-
// | |
// | P1.1|-->MCLK/10 = XT2 HFXTAL/10
// | P5.4/MCLK|-->MCLK = XT2 HFXTAL
//
// B. Nisarga
// Texas Instruments Inc.
// September 2007
// Built with IAR Embedded Workbench Version: 3.42A
//******************************************************************************
#include "msp430x26x.h"
volatile unsigned int i;
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P5DIR |= 0x10; // P5.4= output direction
P5SEL |= 0x10; // P5.4= MCLK option select
P1DIR |= 0x02; // P1.1 = output direction
BCSCTL1 &= ~XT2OFF; // Activate XT2 high freq xtal
BCSCTL3 |= XT2S_2; // 3
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