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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 56 | johboh | 1 | /********************************************************************* |
| 2 | * |
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| 3 | * Ticker service |
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| 4 | * |
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| 5 | ********************************************************************* |
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| 97 | johboh | 6 | * FileName: $HeadURL: https://svn.auml.se/svn/HomeAutomation/trunk/EmbeddedSoftware/PIC/canToSerial/Source/Tick.c $ |
| 7 | * Last changed: $LastChangedDate: 2006-11-14 21:22:17 +0100 (Tue, 14 Nov 2006) $ |
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| 8 | * By: $LastChangedBy: johboh $ |
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| 9 | * Revision: $Revision: 97 $ |
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| 56 | johboh | 10 | ********************************************************************/ |
| 11 | |||
| 12 | #define TICK_INCLUDE |
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| 13 | |||
| 14 | #include <Tick.h> |
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| 15 | #include <Compiler.h> |
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| 16 | |||
| 17 | #define TICK_TEMP_VALUE_1 ((INSTR_FREQ) / (TICKS_PER_SECOND * TICK_PRESCALE_VALUE)) |
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| 18 | |||
| 19 | #if TICK_TEMP_VALUE_1 > 60000 |
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| 20 | #error TICK_PER_SECOND value cannot be programmed with current CLOCK_FREQ |
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| 21 | #error Either lower TICK_PER_SECOND or manually configure the Timer |
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| 22 | #endif |
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| 23 | |||
| 24 | #define TICK_TEMP_VALUE (65535 - TICK_TEMP_VALUE_1) |
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| 25 | |||
| 26 | #define TICK_COUNTER_HIGH ((TICK_TEMP_VALUE >> 8) & 0xff) |
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| 27 | #define TICK_COUNTER_LOW (TICK_TEMP_VALUE & 0xff) |
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| 28 | |||
| 29 | #if (TICK_PRESCALE_VALUE == 2) |
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| 30 | #define TIMER_PRESCALE (0) |
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| 31 | #elif ( TICK_PRESCALE_VALUE == 4 ) |
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| 32 | #define TIMER_PRESCALE (1) |
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| 33 | #elif ( TICK_PRESCALE_VALUE == 8 ) |
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| 34 | #define TIMER_PRESCALE (2) |
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| 35 | #elif ( TICK_PRESCALE_VALUE == 16 ) |
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| 36 | #define TIMER_PRESCALE (3) |
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| 37 | #elif ( TICK_PRESCALE_VALUE == 32 ) |
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| 38 | #define TIMER_PRESCALE (4) |
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| 39 | #elif ( TICK_PRESCALE_VALUE == 64 ) |
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| 40 | #define TIMER_PRESCALE (5) |
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| 41 | #elif ( TICK_PRESCALE_VALUE == 128 ) |
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| 42 | #define TIMER_PRESCALE (6) |
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| 43 | #elif ( TICK_PRESCALE_VALUE == 256 ) |
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| 44 | #define TIMER_PRESCALE (7) |
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| 45 | #else |
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| 46 | #error Invalid TICK_PRESCALE_VALUE specified. |
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| 47 | #endif |
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| 48 | |||
| 49 | |||
| 50 | TICK TickCount = 0; // 10ms/unit |
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| 51 | |||
| 52 | |||
| 53 | |||
| 54 | /* |
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| 55 | * Function: TickInit |
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| 56 | * |
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| 57 | * Input: none |
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| 58 | * Output: Tick manager is initialized. |
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| 59 | * Pre-conditions: TickInit |
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| 60 | * Affects: none |
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| 61 | * Depends: none |
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| 62 | */ |
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| 63 | #define PERIOD (INSTR_FREQ/256/1000)*TICK_PERIOD_MS |
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| 64 | void tickInit(void) |
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| 65 | { |
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| 66 | // Start the timer. |
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| 67 | TMR0L = TICK_COUNTER_LOW; |
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| 68 | TMR0H = TICK_COUNTER_HIGH; |
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| 69 | |||
| 70 | // 16-BIT, internal timer, PSA set to 1:256 |
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| 71 | T0CON = 0b00000000 | TIMER_PRESCALE; |
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| 72 | |||
| 73 | // Start the timer. |
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| 74 | T0CONbits.TMR0ON = 1; |
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| 75 | |||
| 76 | INTCONbits.TMR0IF = 1; |
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| 77 | INTCONbits.TMR0IE = 1; |
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| 78 | } |
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| 79 | |||
| 80 | /* |
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| 81 | * Function: TickGet |
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| 82 | * |
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| 83 | * Input: none |
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| 84 | * Output: Current tick value is given, 1 tick represents approximately 10ms |
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| 85 | * Pre-conditions: TickInit |
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| 86 | * Affects: none |
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| 87 | * Depends: none |
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| 88 | */ |
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| 89 | TICK tickGet(void) |
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| 90 | { |
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| 91 | return TickCount; |
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| 92 | } |
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| 93 | |||
| 94 | |||
| 95 | /* |
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| 96 | * Function: tickUpdate |
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| 97 | * |
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| 98 | * Input: none |
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| 99 | * Output: none |
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| 100 | * Pre-conditions: TickInit |
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| 101 | * Affects: none |
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| 102 | * Depends: none |
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| 103 | */ |
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| 104 | void tickUpdate(void) |
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| 105 | { |
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| 106 | if(INTCONbits.TMR0IF) |
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| 107 | { |
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| 108 | TMR0H = TICK_COUNTER_HIGH; |
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| 109 | TMR0L = TICK_COUNTER_LOW; |
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| 110 | |||
| 111 | TickCount++; |
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| 112 | |||
| 113 | INTCONbits.TMR0IF = 0; |
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| 114 | } |
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| 115 | } |