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/* --COPYRIGHT--,BSD_EX
 * Copyright (c) 2016, 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--*/
//******************************************************************************
//  MSP430FR235x Demo - SAC-L3, DAC Buffer Mode
//
//  Description: Configure SAC-L3 for DAC Buffer Mode. Use the 12 bit DAC to
//  output positive ramp. The OA is set in buffer mode to improve DAC output
//  drive strength. Internal 2.5V reference is selected as DAC reference.
//  Observe the output of OA0O pin with oscilloscope.
//  ACLK = n/a, MCLK = SMCLK = default DCODIV ~1MHz.
//
//                MSP430FR235x
//             -------------------
//         /|\|                   |
//          | |                   |
//          --|RST     DAC12->OA0O|--> P1.1 oscilloscope
//            |                   |
//            |                   |
//            |                   |
//            |                   |
//            |                   |
//
//   Darren Lu
//   Texas Instruments Inc.
//   Oct. 2016
//   Built with IAR Embedded Workbench v6.50 & Code Composer Studio v6.2
//******************************************************************************
#include <msp430.h>

unsigned int DAC_data=0;
unsigned int i=0;
unsigned int sin[50]={2048,2304,2557,2801,3034,3251,3449,3625,3776,3900,
                      3995,4059,4091,4091,4059,3995,3900,3776,3625,3449,
                      3251,3034,2801,2557,2304,2048,1791,1538,1294,1061,
                      844,646,470,319,195,100,36,4,4,36,
                      100,195,319,470,646,844,1061,1294,1538,1791};

int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop watch dog timer

  P1SEL0 |= BIT1;                           // Select P1.1 as OA0O function
  P1SEL1 |= BIT1;                           // OA is used as buffer for DAC

  PM5CTL0 &= ~LOCKLPM5;                     // Disable the GPIO power-on default high-impedance mode
                                            // to activate previously configured port settings

  // Configure reference module
  PMMCTL0_H = PMMPW_H;                      // Unlock the PMM registers
  PMMCTL2 = INTREFEN | REFVSEL_1;           // Enable internal 2V reference
  while(!(PMMCTL2 & REFGENRDY));            // Poll till internal reference settles

  SAC0DAC = DACSREF_1 + DACLSEL_2 + DACIE;  // Select int Vref as DAC reference
  SAC0DAT = sin[0];                       // Initial DAC data
  SAC0DAC |= DACEN;                         // Enable DAC

  SAC0OA = NMUXEN + PMUXEN + PSEL_1 + NSEL_1;//Select positive and negative pin input
  SAC0OA |= OAPM;                            // Select low speed and low power mode
  SAC0PGA = MSEL_1;                          // Set OA as buffer mode
  SAC0OA |= SACEN + OAEN;                    // Enable SAC and OA

  // Use TB2.1 as DAC hardware trigger
  TB2CCR0 = 80-1;                           // PWM Period/2
  TB2CCTL1 = OUTMOD_6;                       // TBCCR1 toggle/set
  TB2CCR1 = 40;                              // TBCCR1 PWM duty cycle
  TB2CTL = TBSSEL__SMCLK | MC_1 | TBCLR;     // SMCLK, up mode, clear TBR

  __bis_SR_register(LPM3_bits + GIE);        // Enter LPM3, Enable Interrupt
}

#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = SAC0_SAC2_VECTOR
__interrupt void SAC0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(SAC0_SAC2_VECTOR))) SAC0_ISR (void)
#else
#error Compiler not supported!
#endif
{
  switch(__even_in_range(SAC0IV,SACIV_4))
  {
    case SACIV_0: break;
    case SACIV_2: break;
    case SACIV_4:
        //DAC_data++;
       // DAC_data &= 0xFFF;
        i++;
        SAC0DAT = sin[i];                 // DAC12 output positive ramp
        if(i==49)
            i=0;
        break;
    default: break;
  }
}


Notite
Gen semnal
Sensibilitatea = Vout = (Vref/ Nrbiti) * NrDAC_DATA = 3.3/4096 * [0...4095]
T = Nep * Tgen
Tgen = 1/10Khz 
Tgen = 0.1

Nep = 50 * 100qs (10kHz) = 5000 microsecunde

0,2 * 10^3 = 200Hz