DAC.rar_C8051F系列单片机_DAC_DAC程序范例_c8051f_单片机dac

//----------------------------------------------------------------------------- // F02x_DACs_SineCosine.c //----------------------------------------------------------------------------- // Copyright 2006 Silicon Laboratories, Inc. // http://www.silabs.com // // Program Description: // // This program outputs sine and cosine waveforms using the hardware DACs // on the C8051F020 microcontroller. The waveforms are output on pins DAC0 // and DAC1. // // The output of the DAC is updated upon a Timer4 interrupt. The Timer4 ISR // then calculates the output of the DACs for the next interrupt. // // The frequency of the output waveforms is set by the #define <FREQUENCY>. // // // How To Test: // // 1) Download the code to an C8051F020 Development Board // 2) Ensure that pins 1 and 2 on the J22 header on the development board // are shorted together. This connects VREF to decoupling capacitors. // 3) Connect two oscillscope probes to pins DAC0 and DAC1. These pins are // available on both the J11 (pins 3 and 4 respectively) and J20 headers // (pin 3 and 4 respectively). // 4) Confirm that there are two waveforms with the output of DAC1 leading // the output DAC0 by 90 degrees. The frequency of both waveforms should // be close to frequency defined by <FREQUENCY> // // FID: 02X000014 // Target: C8051F02x // Tool chain: Keil C51 7.50 / Keil EVAL C51 // Silicon Laboratories IDE version 2.71 // Command Line: Default // // Release 1.0 // -Initial Revision (GP) // -10 JUL 2006 // //----------------------------------------------------------------------------- // Includes //----------------------------------------------------------------------------- #include <c8051f020.h> // SFR declarations //----------------------------------------------------------------------------- // 16-bit SFR Definitions for 'F02x //----------------------------------------------------------------------------- sfr16 RCAP4 = 0xE4; // Timer4 capture/reload sfr16 TMR4 = 0xF4; // Timer4 sfr16 DAC0 = 0xd2; // DAC0 data sfr16 DAC1 = 0xd5; // DAC1 data //----------------------------------------------------------------------------- // Global Constants //----------------------------------------------------------------------------- #define SYSCLK 22118400 // Internal oscillator frequency in Hz #define SAMPLE_RATE_DAC 100000L // DAC sampling rate in Hz #define PHASE_PRECISION 65536 // range of phase accumulator #define FREQUENCY 1000 // Frequency of output waveform in Hz // <PHASE_ADD> is the change in phase between DAC samples; It is used in // the set_DACs routine. unsigned int PHASE_ADD = FREQUENCY * PHASE_PRECISION / SAMPLE_RATE_DAC; int code SINE_TABLE[256] = { 0x0000, 0x0324, 0x0647, 0x096a, 0x0c8b, 0x0fab, 0x12c8, 0x15e2, 0x18f8, 0x1c0b, 0x1f19, 0x2223, 0x2528, 0x2826, 0x2b1f, 0x2e11, 0x30fb, 0x33de, 0x36ba, 0x398c, 0x3c56, 0x3f17, 0x41ce, 0x447a, 0x471c, 0x49b4, 0x4c3f, 0x4ebf, 0x5133, 0x539b, 0x55f5, 0x5842, 0x5a82, 0x5cb4, 0x5ed7, 0x60ec, 0x62f2, 0x64e8, 0x66cf, 0x68a6, 0x6a6d, 0x6c24, 0x6dca, 0x6f5f, 0x70e2, 0x7255, 0x73b5, 0x7504, 0x7641, 0x776c, 0x7884, 0x798a, 0x7a7d, 0x7b5d, 0x7c29, 0x7ce3, 0x7d8a, 0x7e1d, 0x7e9d, 0x7f09, 0x7f62, 0x7fa7, 0x7fd8, 0x7ff6, 0x7fff, 0x7ff6, 0x7fd8, 0x7fa7, 0x7f62, 0x7f09, 0x7e9d, 0x7e1d, 0x7d8a, 0x7ce3, 0x7c29, 0x7b5d, 0x7a7d, 0x798a, 0x7884, 0x776c, 0x7641, 0x7504, 0x73b5, 0x7255, 0x70e2, 0x6f5f, 0x6dca, 0x6c24, 0x6a6d, 0x68a6, 0x66cf, 0x64e8, 0x62f2, 0x60ec, 0x5ed7, 0x5cb4, 0x5a82, 0x5842, 0x55f5, 0x539b, 0x5133, 0x4ebf, 0x4c3f, 0x49b4, 0x471c, 0x447a, 0x41ce, 0x3f17, 0x3c56, 0x398c, 0x36ba, 0x33de, 0x30fb, 0x2e11, 0x2b1f, 0x2826, 0x2528, 0x2223, 0x1f19, 0x1c0b, 0x18f8, 0x15e2, 0x12c8, 0x0fab, 0x0c8b, 0x096a, 0x0647, 0x0324, 0x0000, 0xfcdc, 0xf9b9, 0xf696, 0xf375, 0xf055, 0xed38, 0xea1e, 0xe708, 0xe3f5, 0xe0e7, 0xdddd, 0xdad8, 0xd7da, 0xd4e1, 0xd1ef, 0xcf05, 0xcc22, 0xc946, 0xc674, 0xc3aa, 0xc0e9, 0xbe32, 0xbb86, 0xb8e4, 0xb64c, 0xb3c1, 0xb141, 0xaecd, 0xac65, 0xaa0b, 0xa7be, 0xa57e, 0xa34c, 0xa129, 0x9f14, 0x9d0e, 0x9b18, 0x9931, 0x975a, 0x9593, 0x93dc, 0x9236, 0x90a1, 0x8f1e, 0x8dab, 0x8c4b, 0x8afc, 0x89bf, 0x8894, 0x877c, 0x8676, 0x8583, 0x84a3, 0x83d7, 0x831d, 0x8276, 0x81e3, 0x8163, 0x80f7, 0x809e, 0x8059, 0x8028, 0x800a, 0x8000, 0x800a, 0x8028, 0x8059, 0x809e, 0x80f7, 0x8163, 0x81e3, 0x8276, 0x831d, 0x83d7, 0x84a3, 0x8583, 0x8676, 0x877c, 0x8894, 0x89bf, 0x8afc, 0x8c4b, 0x8dab, 0x8f1e, 0x90a1, 0x9236, 0x93dc, 0x9593, 0x975a, 0x9931, 0x9b18, 0x9d0e, 0x9f14, 0xa129, 0xa34c, 0xa57e, 0xa7be, 0xaa0b, 0xac65, 0xaecd, 0xb141, 0xb3c1, 0xb64c, 0xb8e4, 0xbb86, 0xbe32, 0xc0e9, 0xc3aa, 0xc674, 0xc946, 0xcc22, 0xcf05, 0xd1ef, 0xd4e1, 0xd7da, 0xdad8, 0xdddd, 0xe0e7, 0xe3f5, 0xe708, 0xea1e, 0xed38, 0xf055, 0xf375, 0xf696, 0xf9b9, 0xfcdc, }; //----------------------------------------------------------------------------- // Function Prototypes //----------------------------------------------------------------------------- void main(void); void OSCILLATOR_Init(void); void DAC0_Init (void); void DAC1_Init (void); void TIMER4_Init(int counts); void Set_DACs(void); //----------------------------------------------------------------------------- // MAIN Routine //----------------------------------------------------------------------------- void main (void) { WDTCN = 0xde; // Disable watchdog timer WDTCN = 0xad; OSCILLATOR_Init (); // Initialize oscillator DAC0_Init (); // Initialize DAC0 DAC1_Init (); // Initialize DAC1 TIMER4_Init(SYSCLK/SAMPLE_RATE_DAC);// Initialize Timer4 to overflow // <SAMPLE_RATE_DAC> times per // second EA = 1; // Enable global interrupts while(1); } //----------------------------------------------------------------------------- // Interrupt Service Routines //----------------------------------------------------------------------------- //----------------------------------------------------------------------------- // TIMER4_ISR -- Wave Generator //----------------------------------------------------------------------------- // // This ISR is called on Timer4 overflows. Timer4 is set to auto-reload mode // and is used to schedule the DAC output sample rate in this example. // Note that the value that is written to DAC1 during this ISR call is // actually transferred to DAC1 at the next Timer4 overflow. // //----------------------------------------------------------------------------- void TIMER4_ISR (void) interrupt 16 { T4CON &= ~0x80; // Clear Timer4 overflow flag Set_DACs(); } //----------------------------------------------------------------------------- // Initialization Routines //----------------------------------------------------------------------------- //----------------------------------------------------------------------------- // OSCILLATOR_Init //----------------------------------------------------------------------------- // // Return Value : None // Parameters : None // // This routine initializes the system clock to use an 22.1184MHz crystal // as its clock source. // //----------------------------------------------------------------------------- void OSCILLATOR_Init (void) { int i; // Delay counter OSCXCN = 0x67; // Start external oscillator with