/* --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--*/ //****************************************************************************** // MSP430F20xx Demo - Software Toggle P1.0, MCLK = VLO/8 // // Description; Pulse P1.0 with a 1/100 active duty cycle using software. // Ultra-low frequency ~ 1.5kHz, ultra-low power active mode demonstrated. // ACLK = VL0, MCLK = VLO/8 ~1.5kHz, SMCLK = n/a // // MSP430F20xx // ----------------- // /|\| XIN|- // | | | // --|RST XOUT|- // | | // | P1.0|-->LED // // M.Buccini / L. Westlund // Texas Instruments, Inc // October 2005 // Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.40A //****************************************************************************** #include int main(void) { volatile unsigned int i; // Volatile to prevent removal WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer BCSCTL3 |= LFXT1S_2; // LFXT1 = VLO IFG1 &= ~OFIFG; // Clear OSCFault flag __bis_SR_register(SCG1 + SCG0); // Stop DCO BCSCTL2 |= SELM_3 + DIVM_3; // MCLK = LFXT1/8 P1DIR = 0xFF; // All P1.x outputs P1OUT = 0; // All P1.x reset P2DIR = 0xFF; // All P2.x outputs P2OUT = 0; // All P2.x reset for (;;) { P1OUT |= 0x01; // P1.0 set for (i = 10; i > 0; i--); // Delay 1x P1OUT &= ~0x01; // P1.0 reset for (i = 1000; i > 0; i--); // Delay 100x } }