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#include <c8051f410.h> // SFR declarations
//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for 'F41x
//-----------------------------------------------------------------------------
sfr16 TMR3RL = 0x92; // Timer3 reload value
sfr16 TMR3 = 0x94; // Timer3 counter
sfr16 IDA0 = 0x96; // IDA0 high and low bytes
sfr16 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 = 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 PORT_Init (void);
void DAC0_Init (void);
void DAC1_Init (void);
void TIMER3_Init (int counts);
void Set_DACs (void);
//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------
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 系统频率除以需要的频率，得出需要定时的时间，FFFF减去该数得到定时器的初始值
// <SAMPLE_RATE_DAC> times per second
EA = 1; // Enable global interrupts
while(1); //{} // Wait for interrupt
}
//-----------------------------------------------------------------------------
// Interrupt Service Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// TIMER3_ISR
//-----------------------------------------------------------------------------
//
// This ISR is called on Timer3 overflows. Timer3 is set to auto-reload mode
// and is used to schedule the DAC output sample rate in this example.
// Note that the values written to the DACs during this ISR call are
// actually transferred to the DACs at the next Timer3 overflow.
//
//-----------------------------------------------------------------------------
void TIMER3_ISR (void) interrupt 14
{
TMR3CN =0x04;
// TMR3CN &= ~0x80; // Clear Timer3 overflow flag
Set_DACs();
}
//-----------------------------------------------------------------------------
// Initialization Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This routine initializes the system clock to use the internal 24.5MHz
// oscillator as its clock source. Also enables missing clock detector reset.
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
OSCICN = 0x87; // Set clock to 24.5 MHz
RSTSRC = 0x04; // Enable missing clock detector
}
//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This routine initializes the IDAC pins and enables the crossbar.
//
// P0.0 analog IDA0
// P0.1 analog IDA1
//
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
P0MDIN = 0xFC; // Configure P0.0 and P0.1 to analog ??
P0SKIP = 0x03; // Skip P0.0 and P0.1 on the crossbar
XBR1 = 0x40; // Enable Crossbar
// P0MDOUT=0x00;
}
//-----------------------------------------------------------------------------
// DAC0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure DAC0 to update on Timer3 overflows and enable VDD as VREF
//
//-----------------------------------------------------------------------------
void DAC0_Init(void)
{
REF0CN = 0x0A; // Enable VDD as VREF 还有一个基准电压是怎么回事？
IDA0CN = 0xB3; // Enable IDA0 for 2.0 mA output
// left-justified
// updated on Timer3 overflows
}
//-----------------------------------------------------------------------------
// DAC1_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure DAC1 to update on Timer3 overflows and disable the the VREF buffer
//
//-----------------------------------------------------------------------------
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
}
//-----------------------------------------------------------------------------
// TIMER3_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters :
// 1) int counts - calculated Timer overflow rate
// range is positive range of integer: 0 to 32767
//
// Configure Timer3 to auto-reload at interval specified by <counts> using
// SYSCLK as its time base.
//
//-----------------------------------------------------------------------------
void TIMER3_Init (int counts)
{
TMR3CN = 0x00; // Resets Timer3,
// Sets to 16 bit mode
CKCON |= 0x40; // Use system clock 低字节用系统时钟，
TMR3RL = -counts; // Initial reload value
TMR3 = 0xffff; // Sets timer to reload automatically
EIE1 |= 0x80; // Enable Timer3 interrupts
TMR3CN = 0x04; // Start Timer3
}
//-----------------------------------------------------------------------------
// Support Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// Set_DACs
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Calculates the update values for the two DACs using SINE_TABLE. The DACs
// will actually be updated upon the next Timer3 interrupt. Until that time,
// the DACs will hold their current value.
//
//-----------------------------------------------------------------------------
void Set_DACs(void)
{
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;
SIN_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;
}
//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------
我用的是//-----------------------------------------------------------------------------
// 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 value
sfr16 TMR3 = 0x94; // Timer3 counter
sfr16 IDA0 = 0x96; // IDA0 high and low bytes
sfr16 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 = 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 PORT_Init (void);
void DAC0_Init (void);
void DAC1_Init (void);
void TIMER3_Init (int counts);
void Set_DACs (void);
//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------
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 系统频率除以需要的频率，得出需要定时的时间，FFFF减去该数得到定时器的初始值
// <SAMPLE_RATE_DAC> times per second
EA = 1; // Enable global interrupts
while(1); //{} // Wait for interrupt
}
//-----------------------------------------------------------------------------
// Interrupt Service Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// TIMER3_ISR
//-----------------------------------------------------------------------------
//
// This ISR is called on Timer3 overflows. Timer3 is set to auto-reload mode
// and is used to schedule the DAC output sample rate in this example.
// Note that the values written to the DACs during this ISR call are
// actually transferred to the DACs at the next Timer3 overflow.
//
//-----------------------------------------------------------------------------
void TIMER3_ISR (void) interrupt 14
{
TMR3CN =0x04;
// TMR3CN &= ~0x80; // Clear Timer3 overflow flag
Set_DACs();
}
//-----------------------------------------------------------------------------
// Initialization Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This routine initializes the system clock to use the internal 24.5MHz
// oscillator as its clock source. Also enables missing clock detector reset.
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
OSCICN = 0x87; // Set clock to 24.5 MHz
RSTSRC = 0x04; // Enable missing clock detector
}
//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This routine initializes the IDAC pins and enables the crossbar.
//
// P0.0 analog IDA0
// P0.1 analog IDA1
//
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
P0MDIN = 0xFC; // Configure P0.0 and P0.1 to analog ??
P0SKIP = 0x03; // Skip P0.0 and P0.1 on the crossbar
XBR1 = 0x40; // Enable Crossbar
// P0MDOUT=0x00;
}
//-----------------------------------------------------------------------------
// DAC0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure DAC0 to update on Timer3 overflows and enable VDD as VREF
//
//-----------------------------------------------------------------------------
void DAC0_Init(void)
{
REF0CN = 0x0A; // Enable VDD as VREF 还有一个基准电压是怎么回事？
IDA0CN = 0xB3; // Enable IDA0 for 2.0 mA output
// left-justified
// updated on Timer3 overflows
}
//-----------------------------------------------------------------------------
// DAC1_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure DAC1 to update on Timer3 overflows and disable the the VREF buffer
//
//-----------------------------------------------------------------------------
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
}
//-----------------------------------------------------------------------------
// TIMER3_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters :
// 1) int counts - calculated Timer overflow rate
// range is positive range of integer: 0 to 32767
//
// Configure Timer3 to auto-reload at interval specified by <counts> using
// SYSCLK as its time base.
//
//-----------------------------------------------------------------------------
void TIMER3_Init (int counts)
{
TMR3CN = 0x00; // Resets Timer3,
// Sets to 16 bit mode
CKCON |= 0x40; // Use system clock 低字节用系统时钟，
TMR3RL = -counts; // Initial reload value
TMR3 = 0xffff; // Sets timer to reload automatically
EIE1 |= 0x80; // Enable Timer3 interrupts
TMR3CN = 0x04; // Start Timer3
}
//-----------------------------------------------------------------------------
// Support Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// Set_DACs
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Calculates the update values for the two DACs using SINE_TABLE. The DACs
// will actually be updated upon the next Timer3 interrupt. Until that time,
// the DACs will hold their current value.
//
//-----------------------------------------------------------------------------
void Set_DACs(void)
{
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;
SIN_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;
}
//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------//-----------------------------------------------------------------------------
// 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 value
sfr16 TMR3 = 0x94; // Timer3 counter
sfr16 IDA0 = 0x96; // IDA0 high and low bytes
sfr16 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 = 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 PORT_Init (void);
void DAC0_Init (void);
void DAC1_Init (void);
void TIMER3_Init (int counts);
void Set_DACs (void);
//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------
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 系统频率除以需要的频率，得出需要定时的时间，FFFF减去该数得到定时器的初始值
// <SAMPLE_RATE_DAC> times per second
EA = 1; // Enable global interrupts
while(1); //{} // Wait for interrupt
}
//-----------------------------------------------------------------------------
// Interrupt Service Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// TIMER3_ISR
//-----------------------------------------------------------------------------
//
// This ISR is called on Timer3 overflows. Timer3 is set to auto-reload mode
// and is used to schedule the DAC output sample rate in this example.
// Note that the values written to the DACs during this ISR call are
// actually transferred to the DACs at the next Timer3 overflow.
//
//-----------------------------------------------------------------------------
void TIMER3_ISR (void) interrupt 14
{
TMR3CN =0x04;
// TMR3CN &= ~0x80; // Clear Timer3 overflow flag
Set_DACs();
}
//-----------------------------------------------------------------------------
// Initialization Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This routine initializes the system clock to use the internal 24.5MHz
// oscillator as its clock source. Also enables missing clock detector reset.
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
OSCICN = 0x87; // Set clock to 24.5 MHz
RSTSRC = 0x04; // Enable missing clock detector
}
//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This routine initializes the IDAC pins and enables the crossbar.
//
// P0.0 analog IDA0
// P0.1 analog IDA1
//
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
P0MDIN = 0xFC; // Configure P0.0 and P0.1 to analog ??
P0SKIP = 0x03; // Skip P0.0 and P0.1 on the crossbar
XBR1 = 0x40; // Enable Crossbar
// P0MDOUT=0x00;
}
//-----------------------------------------------------------------------------
// DAC0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure DAC0 to update on Timer3 overflows and enable VDD as VREF
//
//-----------------------------------------------------------------------------
void DAC0_Init(void)
{
REF0CN = 0x0A; // Enable VDD as VREF 还有一个基准电压是怎么回事？
IDA0CN = 0xB3; // Enable IDA0 for 2.0 mA output
// left-justified
// updated on Timer3 overflows
}
//-----------------------------------------------------------------------------
// DAC1_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure DAC1 to update on Timer3 overflows and disable the the VREF buffer
//
//-----------------------------------------------------------------------------
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
}
//-----------------------------------------------------------------------------
// TIMER3_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters :
// 1) int counts - calculated Timer overflow rate
// range is positive range of integer: 0 to 32767
//
// Configure Timer3 to auto-reload at interval specified by <counts> using
// SYSCLK as its time base.
//
//-----------------------------------------------------------------------------
void TIMER3_Init (int counts)
{
TMR3CN = 0x00; // Resets Timer3,
// Sets to 16 bit mode
CKCON |= 0x40; // Use system clock 低字节用系统时钟，
TMR3RL = -counts; // Initial reload value
TMR3 = 0xffff; // Sets timer to reload automatically
EIE1 |= 0x80; // Enable Timer3 interrupts
TMR3CN = 0x04; // Start Timer3
}
//-----------------------------------------------------------------------------
// Support Routines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// Set_DACs
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Calculates the update values for the two DACs using SINE_TABLE. The DACs
// will actually be updated upon the next Timer3 interrupt. Until that time,
// the DACs will hold their current value.
//
//-----------------------------------------------------------------------------
void Set_DACs(void)
{
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;
SIN_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;
}
//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------我用的是c8051f410单片机，以上的端口配置出不来DA的波，是这个配置的问题吗？ |
阿莫论坛20周年了！感谢大家的支持与爱护！！
知道什么是神吗？其实神本来也是人，只不过神做了人做不到的事情 所以才成了神。 （头文字D, 杜汶泽）
|
发表于 2013-7-28 16:19:13
楼主