基於C8051F410的波形發生器設計

這段程式大部分是新華龍公司的官方資料，鄙人稍加修改，簡化了不少代碼，並增加了幾種波形，只要按下P1.4鍵就可以切換。

//-----------------------------------------------------------------------------// F41x_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 C8051F410 microcontroller.  The waveforms are output on pins // P0.0/IDA0 and P0.1/IDA1.//// The output of the DACs is updated upon a Timer3 interrupt.  The Timer3 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 C8051F410 Development Board// 2) Check that the J6 and J16 shorting blocks are not installed.  This //    ensures that the IDAC outputs are not connected to any other pins// 3) Check that the J13 and J14 short blocks are installed. This connects//    the DAC outputs to resistors so that the output current is converted//    to a voltage// 4) Connect two oscillscope probes to pins P0.0/IDA0 and P0.1/IDA1.  //    These pins are available on both the J2 and J11 headers.// 5) 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:            41X000036// Target:         C8051F41x// Tool chain:     Keil C51 7.50 / Keil EVAL C51//                 Silicon Laboratories IDE version 2.71// Command Line:   Default//// Release 1.0//    -Initial Revision (GP)//    -09 AUG 2006////-----------------------------------------------------------------------------// Includes//-----------------------------------------------------------------------------#include <c8051f410.h>                 // SFR declarations//-----------------------------------------------------------------------------// 16-bit SFR Definitions for 'F41x//-----------------------------------------------------------------------------sfr16 TMR3RL   = 0x92;                 // Timer3 reload valuesfr16 TMR3     = 0x94;                 // Timer3 countersfr16 IDA0     = 0x96;                 // IDA0 high and low bytessfr16 IDA1     = 0xF4;                 // IDA1 high and low bytes//-----------------------------------------------------------------------------// Global Constants//-----------------------------------------------------------------------------#define SYSCLK          24500000       // 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 = 1000 * PHASE_PRECISION / SAMPLE_RATE_DAC;//EDIT by lineterunsigned char m;sbit huan=P1^4;//EDIT OVERunsigned int code SINE_TABLE[128] = {   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,};//-----------------------------------------------------------------------------// Function Prototypes//-----------------------------------------------------------------------------void main(void);void OSCILLATOR_Init (void);void PORT_Init (void);void DAC0_Init (void);void DAC1_Init (void);void TIMER3_Init (int counts);void Set_DACs (void);void main (void) {   PCA0MD &= ~0x40;                    // Disable Watchdog timer   OSCILLATOR_Init ();                 // Initialize oscillator   PORT_Init ();                       // Initialize crossbar and ports   DAC0_Init ();                       // Initialize DAC0   DAC1_Init ();                       // Initialize DAC1         TIMER3_Init(SYSCLK/SAMPLE_RATE_DAC);// Initialize Timer3 to overflow at                                        // <SAMPLE_RATE_DAC> times per second   EA = 1;                             // Enable global interrupts   m=0;   while(1)    {while(huan!=1){m++;m%=4;while(huan!=1);}   }                         // Wait for interrupt} void TIMER3_ISR (void) interrupt 14{   TMR3CN &= ~0x80;                   // Clear Timer3 overflow flag    Set_DACs();}void OSCILLATOR_Init (void){   OSCICN  = 0x87;                     // Set clock to 24.5 MHz   RSTSRC  = 0x04;                     // Enable missing clock detector}void PORT_Init (void){   P0MDIN    &= ~0x03;                   // Configure P0.0 and P0.1 to analog   P0SKIP    |= 0x03;                   // Skip P0.0 and P0.1 on the crossbar   P1MDOUT &= ~0x10;   XBR1      = 0x40;                   // Enable Crossbar}void DAC0_Init(void){   REF0CN = 0x0A;                      // Enable VDD as VREF   IDA0CN = 0xB3;                      // Enable IDA0 for 2.0 mA output                                       // left-justified                                        // updated on Timer3 overflows}void DAC1_Init(void){   REF0CN = 0x0A;                      // Enable VDD as VREF   IDA1CN = 0xB3;                      // Enable IDA0 for 2.0 mA output                                       // left-justified                                        // updated on Timer3 overflows}void TIMER3_Init (int counts){      TMR3CN  = 0x00;                     // Resets Timer3,                                        // Sets to 16 bit mode   CKCON  |= 0x40;                     // Use system clock   TMR3RL  = -counts;                  // Initial reload value   TMR3    = 0xffff;                   // Sets timer to reload automatically   EIE1   |= 0x80;                     // Enable Timer3 interrupts   TMR3CN  = 0x04;                     // Start Timer3}void Set_DACs(void){   if (0==m)   {   static unsigned phase_acc = 0;      // Holds phase accumulator   int SIN_temp, COS_temp;             // Temporary 16-bit variables    unsigned char index;                // Index into SINE table   phase_acc += PHASE_ADD;             // Increment phase accumulator   index = phase_acc >> 8;      if(index&0x80)if(index&0x40)SIN_temp = 0xffff-SINE_TABLE[63-index&0x3f];       // Read the table valueelseSIN_temp = 0xffff-SINE_TABLE[index&0x3f];       // Read the table valueelseif(index&0x40)   SIN_temp = SINE_TABLE[127-index];       // Read the table valueelseSIN_temp = SINE_TABLE[index];       // Read the table value      index += 64;                        // 90 degree phase shift    COS_temp = SINE_TABLE[index];   // Add a DC bias to change the the rails from a bipolar (-32768 to 32767)   // to unipolar (0 to 65535)   // Note: the XOR with 0x8000 translates the bipolar quantity into    // a unipolar quantity.   IDA0 = SIN_temp ^ 0x8000;             // Update DAC values   IDA1 = COS_temp ^ 0x8000;           }else if (1==m){static unsigned char fang=0;fang++;fang%=100;if (fang<50){IDA0=0;}else{IDA0=0x0ffff;}}else if (2==m){static unsigned char fang=0;unsigned int san1;fang++;fang%=100;if (fang<50){san1=fang<<10;IDA0=san1;}else{san1=(100-fang)<<10;IDA0=san1;}}else if (3==m){static unsigned char fang=0;unsigned int san1;fang++;fang%=100;san1=fang<<9;IDA0=san1;}}//-----------------------------------------------------------------------------// End Of File//-----------------------------------------------------------------------------

注意連接埠輸出模式配置，弄錯了會燒單片機的。