//******************************************************************************
//   MSP430F23x0 Demo - Timer_B, PWM TB1-2, Up/Down Mode, 32kHz ACLK
//
//   Description: This program generates two PWM outputs on P4.1,2 using
//   Timer_B configured for up/down mode. The value in TBCCR0, 128, defines
//   the PWM period/2 and the values in TBCCR1-2 the PWM duty cycles. Using
//   32kHz ACLK as TBCLK, the timer period is 7.8ms with a 75% duty
//   cycle on P4.1 and 25% on P4.2. Normal operating mode is LPM3.
//   ACLK = TBCLK = LFXT1 = 32768Hz, MCLK = default DCO ~1.2MHz
//   //* External watch crystal on XIN XOUT is required for ACLK *//
//
//                MSP430F23x0
//             -----------------
//         /|\|              XIN|-
//          | |                 | 32kHz
//          --|RST          XOUT|-
//            |                 |
//            |         P4.1/TB1|--> TBCCR1 - 75% PWM
//            |         P4.2/TB2|--> TBCCR2 - 25% PWM
//
//   A. Dannenberg
//   Texas Instruments Inc.
//   January 2007
//   Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.41A
//******************************************************************************
#include "msp430x23x0.h"

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  P4DIR |= 0x06;                            // P4.1 and P4.2 output
  P4SEL |= 0x06;                            // P4.1 and P4.2 TB1/2 otions
  TBCCR0 = 128;                             // PWM Period/2
  TBCCTL1 = OUTMOD_6;                       // TBCCR1 toggle/set
  TBCCR1 = 32;                              // TBCCR1 PWM Duty Cycle
  TBCCTL2 = OUTMOD_6;                       // TBCCR2 toggle/set
  TBCCR2 = 96;                              // TBCCR2 PWM duty cycle
  TBCTL = TBSSEL_1 + MC_3;                  // ACLK, updown mode

  __bis_SR_register(LPM3_bits);             // Enter LPM3
}