1 | //-----------------------------------------------------------------------------
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2 | // Includes
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3 | //-----------------------------------------------------------------------------
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4 | #include <c8051f310.h> // SFR declarations
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5 |
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6 | unsigned long ms;
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7 |
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8 | //-----------------------------------------------------------------------------
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9 | // 16-bit SFR Definitions for 'F33x
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10 | //-----------------------------------------------------------------------------
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11 |
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12 | sfr16 TMR2RL = 0xca; // Timer2 reload value
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13 | sfr16 TMR2 = 0xcc; // Timer2 counter
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14 | //-----------------------------------------------------------------------------
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15 | // Global CONSTANTS
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16 | //-----------------------------------------------------------------------------
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17 |
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18 | #define SYSCLK 24500000 // SYSCLK frequency in Hz
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19 |
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20 | sbit LED = P0^3; // LED='1' means ON
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21 |
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22 | //-----------------------------------------------------------------------------
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23 | // Function PROTOTYPES
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24 | //-----------------------------------------------------------------------------
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25 | void SYSCLK_Init (void);
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26 | void PORT_Init (void);
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27 | void Timer2_Init (void);
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28 | void Timer2_ISR (void);
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29 | void ADC0_Init (void);
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30 | void ADC0_ISR (void);
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31 |
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32 | //-----------------------------------------------------------------------------
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33 | // MAIN Routine
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34 | //-----------------------------------------------------------------------------
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35 | void main (void) {
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36 |
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37 | unsigned long wait;
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38 |
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39 | ms=0;
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40 | wait=0;
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41 |
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42 | // disable watchdog timer
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43 | PCA0MD &= ~0x40; // WDTE = 0 (clear watchdog timer
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44 | // enable)
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45 |
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46 | SYSCLK_Init (); // Initialize system clock to
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47 | // 24.5MHz
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48 | PORT_Init (); // Initialize crossbar and GPIO
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49 | Timer2_Init (); // Init Timer2
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50 |
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51 | EA = 1; // enable global interrupts
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52 | while (1) { // spin forever
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53 | if( (ms-wait) < 1000 ) {
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54 | LED=~LED;
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55 | wait=ms;
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56 | }
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57 |
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58 | }
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59 | }
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60 |
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61 | //-----------------------------------------------------------------------------
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62 | // SYSCLK_Init
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63 | //-----------------------------------------------------------------------------
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64 | //
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65 | // This routine initializes the system clock to use the internal 24.5MHz
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66 | // oscillator as its clock source. Also enables missing clock detector reset.
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67 | //
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68 | void SYSCLK_Init (void)
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69 | {
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70 |
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71 | OSCICN = 0xC3; // configure internal oscillator for
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72 |
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73 | RSTSRC = 0x04; // enable missing clock detector
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74 | }
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75 |
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76 | //-----------------------------------------------------------------------------
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77 | // PORT_Init
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78 | //-----------------------------------------------------------------------------
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79 | //
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80 | // Configure the Crossbar and GPIO ports.
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81 | // P0.3 - LED (push-pull)
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82 | //
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83 | void PORT_Init (void)
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84 | {
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85 |
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86 | XBR0 = 0x00; // no digital peripherals selected
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87 | XBR1 = 0x40; // Enable crossbar and weak pull-ups
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88 | P0MDOUT |= 0x08; // enable LED as a push-pull output
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89 | }
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90 |
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91 | //-----------------------------------------------------------------------------
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92 | // Timer2_Init
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93 | //-----------------------------------------------------------------------------
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94 | //
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95 | // Configure Timer2 to 16-bit auto-reload and generate an interrupt
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96 | //
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97 | void Timer2_Init (void)
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98 | {
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99 | TMR2CN = 0x00; // Stop Timer2; Clear TF2;
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100 | // use SYSCLK/12 as timebase
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101 | CKCON &= ~0x20; // Timer2 clocked based on T2XCLK;
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102 |
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103 | TMR2RL = -SYSCLK/12/1000; // Init reload values
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104 | TMR2 = 0xffff; // set to reload immediately
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105 | ET2 = 1; // enable Timer2 interrupts
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106 | TR2 = 1; // start Timer2
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107 | }
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108 |
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109 |
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110 | //-----------------------------------------------------------------------------
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111 | // Interrupt Service Routines
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112 | //-----------------------------------------------------------------------------
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113 |
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114 | //-----------------------------------------------------------------------------
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115 | // Timer2_ISR
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116 | //-----------------------------------------------------------------------------
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117 | // This routine changes the state of the LED whenever Timer2 overflows.
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118 | //
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119 | void Timer2_ISR (void) interrupt 5
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120 | {
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121 | TF2H = 0; // clear Timer2 interrupt flag
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122 | ms++;
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123 | }
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