temp_3.c

F120的最小系统,可以让初学者学习一下.方便好用

void SYSCLK_Init (void)
{
   int i;                              // software timer

   char SFRPAGE_SAVE = SFRPAGE;        // Save Current SFR page

   SFRPAGE = CONFIG_PAGE;              // set SFR page

   OSCICN = 0x83;                      // set internal oscillator to run
                                       // at its maximum frequency

   CLKSEL = 0x00;                      // Select the internal osc. as
                                       // the SYSCLK source

   //Turn on the PLL and increase the system clock by a factor of M/N = 2
   SFRPAGE = CONFIG_PAGE;

   PLL0CN  = 0x00;                     // Set internal osc. as PLL source
   SFRPAGE = LEGACY_PAGE;
   FLSCL   = 0x10;                     // Set FLASH read time for 50MHz clk
                                       // or less
   SFRPAGE = CONFIG_PAGE;
   PLL0CN |= 0x01;                     // Enable Power to PLL
   PLL0DIV = 0x01;                     // Set Pre-divide value to N (N = 1)
   PLL0FLT = 0x01;                     // Set the PLL filter register for
                                       // a reference clock from 19 - 30 MHz
                                       // and an output clock from 45 - 80 MHz
   PLL0MUL = 0x02;                     // Multiply SYSCLK by M (M = 2)

   for (i=0; i < 256; i++) ;           // Wait at least 5us
   PLL0CN  |= 0x02;                    // Enable the PLL
   while(!(PLL0CN & 0x10));            // Wait until PLL frequency is locked
   CLKSEL  = 0x02;                     // Select PLL as SYSCLK source

   SFRPAGE = SFRPAGE_SAVE;             // Restore SFR page
}

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// This routine configures the crossbar and GPIO ports.
//
void PORT_Init (void)
{
   char SFRPAGE_SAVE = SFRPAGE;        // Save Current SFR page

   SFRPAGE = CONFIG_PAGE;              // set SFR page

   XBR0     = 0x00;
   XBR1     = 0x00;
   XBR2     = 0x44;                    // Enable crossbar and weak pull-up
                                       // Enable UART1

   P0MDOUT |= 0x01;                    // Set TX1 pin to push-pull
   P1MDOUT |= 0x40;                    // Set P1.6(LED) to push-pull

   SFRPAGE = SFRPAGE_SAVE;             // Restore SFR page
}

//-----------------------------------------------------------------------------
// UART1_Init
//-----------------------------------------------------------------------------
//
// Configure the UART1 using Timer1, for <baudrate> and 8-N-1.
//
void UART1_Init (void)
{
   char SFRPAGE_SAVE = SFRPAGE;        // Save Current SFR page

   SFRPAGE = UART1_PAGE;
   SCON1   = 0x10;                     // SCON1: mode 0, 8-bit UART, enable RX

   SFRPAGE = TIMER01_PAGE;
   TMOD   &= ~0xF0;
   TMOD   |=  0x20;                    // TMOD: timer 1, mode 2, 8-bit reload


   if (SYSCLK/BAUDRATE/2/256 < 1) {
      TH1 = -(SYSCLK/BAUDRATE/2);
      CKCON |= 0x10;                   // T1M = 1; SCA1:0 = xx
   } else if (SYSCLK/BAUDRATE/2/256 < 4) {
      TH1 = -(SYSCLK/BAUDRATE/2/4);
      CKCON &= ~0x13;                  // Clear all T1 related bits
      CKCON |=  0x01;                  // T1M = 0; SCA1:0 = 01
   } else if (SYSCLK/BAUDRATE/2/256 < 12) {
      TH1 = -(SYSCLK/BAUDRATE/2/12);
      CKCON &= ~0x13;                  // T1M = 0; SCA1:0 = 00
   } else {
      TH1 = -(SYSCLK/BAUDRATE/2/48);
      CKCON &= ~0x13;                  // Clear all T1 related bits
      CKCON |=  0x02;                  // T1M = 0; SCA1:0 = 10
   }

   TL1 = TH1;                          // initialize Timer1
   TR1 = 1;                            // start Timer1

   SFRPAGE = UART1_PAGE;
   TI1 = 1;                            // Indicate TX1 ready

   SFRPAGE = SFRPAGE_SAVE;             // Restore SFR page

}

//-----------------------------------------------------------------------------
// ADC0_Init
//-----------------------------------------------------------------------------
//
// Configure ADC0 to use Timer3 overflows as conversion source, to
// generate an interrupt on conversion complete, and to use left-justified
// output mode.  Enables ADC end of conversion interrupt. Leaves ADC disabled.
//
void ADC0_Init (void)
{
   char SFRPAGE_SAVE = SFRPAGE;        // Save Current SFR page

   SFRPAGE = ADC0_PAGE;

   ADC0CN = 0x05;                      // ADC0 disabled; normal tracking
                                       // mode; ADC0 conversions are initiated
                                       // on overflow of Timer3; ADC0 data is
                                       // left-justified
   REF0CN = 0x07;                      // enable temp sensor, on-chip VREF,
                                       // and VREF output buffer
   AMX0SL = 0x0f;                      // Select TEMP sens as ADC mux output
   ADC0CF = (SYSCLK/2500000) << 3;     // ADC conversion clock = 2.5MHz
   ADC0CF |= 0x01;                     // PGA gain = 2

   EIE2 |= 0x02;                       // enable ADC interrupts

   SFRPAGE = SFRPAGE_SAVE;             // Restore SFR page
}

//-----------------------------------------------------------------------------
// Timer3_Init
//-----------------------------------------------------------------------------
//
// Configure Timer3 to auto-reload at interval specified by <counts> (no
// interrupt generated) using SYSCLK as its time base.
//
void Timer3_Init (int counts)
{
   char SFRPAGE_SAVE = SFRPAGE;        // Save Current SFR page

   SFRPAGE = TMR3_PAGE;

   TMR3CN = 0x00;                      // Stop Timer3; Clear TF3;
   TMR3CF = 0x08;                      // use SYSCLK as timebase

   RCAP3   = -counts;                  // Init reload values
   TMR3    = RCAP3;                    // set to reload immediately
   EIE2   &= ~0x01;                    // disable Timer3 interrupts
   TR3 = 1;                            // start Timer3

   SFRPAGE = SFRPAGE_SAVE;             // Restore SFR page
}

//-----------------------------------------------------------------------------
// Interrupt Service Routines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// ADC0_ISR
//-----------------------------------------------------------------------------
//
// ADC0 end-of-conversion ISR
// Here we take the ADC0 sample, add it to a running total <accumulator>, and
// decrement our local decimation counter <int_dec>.  When <int_dec> reaches
// zero, we post the decimated result in the global variable <result>.
//
void ADC0_ISR (void) interrupt 15
{
   static unsigned int_dec=INT_DEC;    // integrate/decimate counter
                                       // we post a new result when
                                       // int_dec = 0
   static long accumulator=0L;         // here's where we integrate the
                                       // ADC samples

   AD0INT = 0;                         // clear ADC conversion complete
                                       // indicator

   accumulator += ADC0;                // read ADC value and add to running
                                       // total
   int_dec--;                          // update decimation counter

   if (int_dec == 0) {                 // if zero, then post result
      int_dec = INT_DEC;               // reset counter
      result = accumulator >> 8;
      accumulator = 0L;                // reset accumulator
   }
}