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1 | 32 | kaklik | /********************************************************************* |
2 | * |
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3 | * Tick Manager for Timekeeping |
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4 | * |
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5 | ********************************************************************* |
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6 | * FileName: Tick.c |
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7 | * Dependencies: Timer 0 (PIC18) or Timer 1 (PIC24F, PIC24H, |
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8 | * dsPIC30F, dsPIC33F, PIC32) |
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9 | * Processor: PIC18, PIC24F, PIC24H, dsPIC30F, dsPIC33F, PIC32 |
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10 | * Compiler: Microchip C32 v1.10b or higher |
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11 | * Microchip C30 v3.12 or higher |
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12 | * Microchip C18 v3.30 or higher |
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13 | * HI-TECH PICC-18 PRO 9.63PL2 or higher |
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14 | * Company: Microchip Technology, Inc. |
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15 | * |
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16 | * Software License Agreement |
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17 | * |
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18 | * Copyright (C) 2002-2010 Microchip Technology Inc. All rights |
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19 | * reserved. |
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20 | * |
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21 | * Microchip licenses to you the right to use, modify, copy, and |
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22 | * distribute: |
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23 | * (i) the Software when embedded on a Microchip microcontroller or |
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24 | * digital signal controller product ("Device") which is |
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25 | * integrated into Licensee's product; or |
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26 | * (ii) ONLY the Software driver source files ENC28J60.c, ENC28J60.h, |
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27 | * ENCX24J600.c and ENCX24J600.h ported to a non-Microchip device |
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28 | * used in conjunction with a Microchip ethernet controller for |
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29 | * the sole purpose of interfacing with the ethernet controller. |
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30 | * |
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31 | * You should refer to the license agreement accompanying this |
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32 | * Software for additional information regarding your rights and |
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33 | * obligations. |
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34 | * |
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35 | * THE SOFTWARE AND DOCUMENTATION ARE PROVIDED "AS IS" WITHOUT |
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36 | * WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT |
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37 | * LIMITATION, ANY WARRANTY OF MERCHANTABILITY, FITNESS FOR A |
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38 | * PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
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39 | * MICROCHIP BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR |
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40 | * CONSEQUENTIAL DAMAGES, LOST PROFITS OR LOST DATA, COST OF |
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41 | * PROCUREMENT OF SUBSTITUTE GOODS, TECHNOLOGY OR SERVICES, ANY CLAIMS |
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42 | * BY THIRD PARTIES (INCLUDING BUT NOT LIMITED TO ANY DEFENSE |
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43 | * THEREOF), ANY CLAIMS FOR INDEMNITY OR CONTRIBUTION, OR OTHER |
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44 | * SIMILAR COSTS, WHETHER ASSERTED ON THE BASIS OF CONTRACT, TORT |
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45 | * (INCLUDING NEGLIGENCE), BREACH OF WARRANTY, OR OTHERWISE. |
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46 | * |
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47 | * |
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48 | * Author Date Comment |
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49 | *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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50 | * Nilesh Rajbharti 6/28/01 Original (Rev 1.0) |
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51 | * Nilesh Rajbharti 2/9/02 Cleanup |
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52 | * Nilesh Rajbharti 5/22/02 Rev 2.0 (See version.log for detail) |
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53 | * Howard Schlunder 6/13/07 Changed to use timer without |
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54 | * writing for perfect accuracy. |
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55 | ********************************************************************/ |
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56 | #define __TICK_C |
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57 | |||
58 | #include "TCPIP Stack/TCPIP.h" |
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59 | |||
60 | // Internal counter to store Ticks. This variable is incremented in an ISR and |
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61 | // therefore must be marked volatile to prevent the compiler optimizer from |
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62 | // reordering code to use this value in the main context while interrupts are |
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63 | // disabled. |
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64 | static volatile DWORD dwInternalTicks = 0; |
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65 | |||
66 | // 6-byte value to store Ticks. Allows for use over longer periods of time. |
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67 | static BYTE vTickReading[6]; |
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68 | |||
69 | static void GetTickCopy(void); |
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70 | |||
71 | |||
72 | /***************************************************************************** |
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73 | Function: |
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74 | void TickInit(void) |
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75 | |||
76 | Summary: |
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77 | Initializes the Tick manager module. |
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78 | |||
79 | Description: |
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80 | Configures the Tick module and any necessary hardware resources. |
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81 | |||
82 | Precondition: |
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83 | None |
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84 | |||
85 | Parameters: |
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86 | None |
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87 | |||
88 | Returns: |
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89 | None |
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90 | |||
91 | Remarks: |
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92 | This function is called only one during lifetime of the application. |
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93 | ***************************************************************************/ |
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94 | void TickInit(void) |
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95 | { |
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96 | #if defined(__18CXX) |
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97 | // Use Timer0 for 8 bit processors |
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98 | // Initialize the time |
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99 | TMR0H = 0; |
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100 | TMR0L = 0; |
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101 | |||
102 | // Set up the timer interrupt |
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103 | INTCON2bits.TMR0IP = 0; // Low priority |
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104 | INTCONbits.TMR0IF = 0; |
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105 | INTCONbits.TMR0IE = 1; // Enable interrupt |
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106 | |||
107 | // Timer0 on, 16-bit, internal timer, 1:256 prescalar |
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108 | T0CON = 0x87; |
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109 | |||
110 | #else |
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111 | // Use Timer 1 for 16-bit and 32-bit processors |
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112 | // 1:256 prescale |
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113 | T1CONbits.TCKPS = 3; |
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114 | // Base |
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115 | PR1 = 0xFFFF; |
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116 | // Clear counter |
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117 | TMR1 = 0; |
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118 | |||
119 | // Enable timer interrupt |
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120 | #if defined(__C30__) |
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121 | IPC0bits.T1IP = 2; // Interrupt priority 2 (low) |
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122 | IFS0bits.T1IF = 0; |
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123 | IEC0bits.T1IE = 1; |
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124 | #else |
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125 | IPC1bits.T1IP = 2; // Interrupt priority 2 (low) |
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126 | IFS0CLR = _IFS0_T1IF_MASK; |
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127 | IEC0SET = _IEC0_T1IE_MASK; |
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128 | #endif |
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129 | |||
130 | // Start timer |
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131 | T1CONbits.TON = 1; |
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132 | #endif |
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133 | } |
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134 | |||
135 | /***************************************************************************** |
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136 | Function: |
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137 | static void GetTickCopy(void) |
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138 | |||
139 | Summary: |
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140 | Reads the tick value. |
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141 | |||
142 | Description: |
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143 | This function performs an interrupt-safe and synchronized read of the |
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144 | 48-bit Tick value. |
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145 | |||
146 | Precondition: |
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147 | None |
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148 | |||
149 | Parameters: |
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150 | None |
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151 | |||
152 | Returns: |
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153 | None |
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154 | ***************************************************************************/ |
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155 | static void GetTickCopy(void) |
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156 | { |
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157 | // Perform an Interrupt safe and synchronized read of the 48-bit |
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158 | // tick value |
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159 | #if defined(__18CXX) |
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160 | do |
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161 | { |
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162 | INTCONbits.TMR0IE = 1; // Enable interrupt |
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163 | Nop(); |
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164 | INTCONbits.TMR0IE = 0; // Disable interrupt |
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165 | vTickReading[0] = TMR0L; |
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166 | vTickReading[1] = TMR0H; |
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167 | *((DWORD*)&vTickReading[2]) = dwInternalTicks; |
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168 | } while(INTCONbits.TMR0IF); |
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169 | INTCONbits.TMR0IE = 1; // Enable interrupt |
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170 | #elif defined(__C30__) |
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171 | do |
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172 | { |
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173 | DWORD dwTempTicks; |
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174 | |||
175 | IEC0bits.T1IE = 1; // Enable interrupt |
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176 | Nop(); |
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177 | IEC0bits.T1IE = 0; // Disable interrupt |
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178 | |||
179 | // Get low 2 bytes |
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180 | ((WORD*)vTickReading)[0] = TMR1; |
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181 | |||
182 | // Correct corner case where interrupt increments byte[4+] but |
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183 | // TMR1 hasn't rolled over to 0x0000 yet |
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184 | dwTempTicks = dwInternalTicks; |
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185 | if(((WORD*)vTickReading)[0] == 0xFFFFu) |
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186 | dwTempTicks--; |
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187 | |||
188 | // Get high 4 bytes |
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189 | vTickReading[2] = ((BYTE*)&dwTempTicks)[0]; |
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190 | vTickReading[3] = ((BYTE*)&dwTempTicks)[1]; |
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191 | vTickReading[4] = ((BYTE*)&dwTempTicks)[2]; |
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192 | vTickReading[5] = ((BYTE*)&dwTempTicks)[3]; |
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193 | } while(IFS0bits.T1IF); |
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194 | IEC0bits.T1IE = 1; // Enable interrupt |
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195 | #else // PIC32 |
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196 | do |
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197 | { |
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198 | DWORD dwTempTicks; |
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199 | |||
200 | IEC0SET = _IEC0_T1IE_MASK; // Enable interrupt |
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201 | Nop(); |
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202 | IEC0CLR = _IEC0_T1IE_MASK; // Disable interrupt |
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203 | |||
204 | // Get low 2 bytes |
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205 | ((volatile WORD*)vTickReading)[0] = TMR1; |
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206 | |||
207 | // Correct corner case where interrupt increments byte[4+] but |
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208 | // TMR1 hasn't rolled over to 0x0000 yet |
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209 | dwTempTicks = dwInternalTicks; |
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210 | |||
211 | // PIC32MX3XX/4XX devices trigger the timer interrupt when TMR1 == PR1 |
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212 | // (TMR1 prescalar is 0x00), requiring us to undo the ISR's increment |
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213 | // of the upper 32 bits of our 48 bit timer in the special case when |
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214 | // TMR1 == PR1 == 0xFFFF. For other PIC32 families, the ISR is |
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215 | // triggered when TMR1 increments from PR1 to 0x0000, making no special |
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216 | // corner case. |
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217 | #if __PIC32_FEATURE_SET__ <= 460 |
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218 | if(((WORD*)vTickReading)[0] == 0xFFFFu) |
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219 | dwTempTicks--; |
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220 | #elif !defined(__PIC32_FEATURE_SET__) |
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221 | #error __PIC32_FEATURE_SET__ macro must be defined. You need to download a newer C32 compiler version. |
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222 | #endif |
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223 | |||
224 | // Get high 4 bytes |
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225 | vTickReading[2] = ((BYTE*)&dwTempTicks)[0]; |
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226 | vTickReading[3] = ((BYTE*)&dwTempTicks)[1]; |
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227 | vTickReading[4] = ((BYTE*)&dwTempTicks)[2]; |
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228 | vTickReading[5] = ((BYTE*)&dwTempTicks)[3]; |
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229 | } while(IFS0bits.T1IF); |
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230 | IEC0SET = _IEC0_T1IE_MASK; // Enable interrupt |
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231 | #endif |
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232 | } |
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233 | |||
234 | |||
235 | /***************************************************************************** |
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236 | Function: |
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237 | DWORD TickGet(void) |
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238 | |||
239 | Summary: |
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240 | Obtains the current Tick value. |
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241 | |||
242 | Description: |
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243 | This function retrieves the current Tick value, allowing timing and |
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244 | measurement code to be written in a non-blocking fashion. This function |
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245 | retrieves the least significant 32 bits of the internal tick counter, |
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246 | and is useful for measuring time increments ranging from a few |
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247 | microseconds to a few hours. Use TickGetDiv256 or TickGetDiv64K for |
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248 | longer periods of time. |
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249 | |||
250 | Precondition: |
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251 | None |
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252 | |||
253 | Parameters: |
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254 | None |
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255 | |||
256 | Returns: |
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257 | Lower 32 bits of the current Tick value. |
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258 | ***************************************************************************/ |
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259 | DWORD TickGet(void) |
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260 | { |
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261 | GetTickCopy(); |
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262 | return *((DWORD*)&vTickReading[0]); |
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263 | } |
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264 | |||
265 | /***************************************************************************** |
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266 | Function: |
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267 | DWORD TickGetDiv256(void) |
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268 | |||
269 | Summary: |
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270 | Obtains the current Tick value divided by 256. |
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271 | |||
272 | Description: |
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273 | This function retrieves the current Tick value, allowing timing and |
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274 | measurement code to be written in a non-blocking fashion. This function |
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275 | retrieves the middle 32 bits of the internal tick counter, |
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276 | and is useful for measuring time increments ranging from a few |
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277 | minutes to a few weeks. Use TickGet for shorter periods or TickGetDiv64K |
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278 | for longer ones. |
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279 | |||
280 | Precondition: |
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281 | None |
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282 | |||
283 | Parameters: |
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284 | None |
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285 | |||
286 | Returns: |
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287 | Middle 32 bits of the current Tick value. |
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288 | ***************************************************************************/ |
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289 | DWORD TickGetDiv256(void) |
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290 | { |
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291 | DWORD dw; |
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292 | |||
293 | GetTickCopy(); |
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294 | ((BYTE*)&dw)[0] = vTickReading[1]; // Note: This copy must be done one |
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295 | ((BYTE*)&dw)[1] = vTickReading[2]; // byte at a time to prevent misaligned |
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296 | ((BYTE*)&dw)[2] = vTickReading[3]; // memory reads, which will reset the PIC. |
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297 | ((BYTE*)&dw)[3] = vTickReading[4]; |
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298 | |||
299 | return dw; |
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300 | } |
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301 | |||
302 | /***************************************************************************** |
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303 | Function: |
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304 | DWORD TickGetDiv64K(void) |
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305 | |||
306 | Summary: |
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307 | Obtains the current Tick value divided by 64K. |
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308 | |||
309 | Description: |
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310 | This function retrieves the current Tick value, allowing timing and |
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311 | measurement code to be written in a non-blocking fashion. This function |
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312 | retrieves the most significant 32 bits of the internal tick counter, |
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313 | and is useful for measuring time increments ranging from a few |
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314 | days to a few years, or for absolute time measurements. Use TickGet or |
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315 | TickGetDiv256 for shorter periods of time. |
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316 | |||
317 | Precondition: |
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318 | None |
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319 | |||
320 | Parameters: |
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321 | None |
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322 | |||
323 | Returns: |
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324 | Upper 32 bits of the current Tick value. |
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325 | ***************************************************************************/ |
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326 | DWORD TickGetDiv64K(void) |
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327 | { |
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328 | DWORD dw; |
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329 | |||
330 | GetTickCopy(); |
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331 | ((BYTE*)&dw)[0] = vTickReading[2]; // Note: This copy must be done one |
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332 | ((BYTE*)&dw)[1] = vTickReading[3]; // byte at a time to prevent misaligned |
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333 | ((BYTE*)&dw)[2] = vTickReading[4]; // memory reads, which will reset the PIC. |
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334 | ((BYTE*)&dw)[3] = vTickReading[5]; |
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335 | |||
336 | return dw; |
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337 | } |
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338 | |||
339 | |||
340 | /***************************************************************************** |
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341 | Function: |
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342 | DWORD TickConvertToMilliseconds(DWORD dwTickValue) |
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343 | |||
344 | Summary: |
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345 | Converts a Tick value or difference to milliseconds. |
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346 | |||
347 | Description: |
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348 | This function converts a Tick value or difference to milliseconds. For |
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349 | example, TickConvertToMilliseconds(32768) returns 1000 when a 32.768kHz |
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350 | clock with no prescaler drives the Tick module interrupt. |
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351 | |||
352 | Precondition: |
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353 | None |
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354 | |||
355 | Parameters: |
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356 | dwTickValue - Value to convert to milliseconds |
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357 | |||
358 | Returns: |
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359 | Input value expressed in milliseconds. |
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360 | |||
361 | Remarks: |
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362 | This function performs division on DWORDs, which is slow. Avoid using |
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363 | it unless you absolutely must (such as displaying data to a user). For |
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364 | timeout comparisons, compare the current value to a multiple or fraction |
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365 | of TICK_SECOND, which will be calculated only once at compile time. |
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366 | ***************************************************************************/ |
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367 | DWORD TickConvertToMilliseconds(DWORD dwTickValue) |
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368 | { |
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369 | return (dwTickValue+(TICKS_PER_SECOND/2000ul))/((DWORD)(TICKS_PER_SECOND/1000ul)); |
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370 | } |
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371 | |||
372 | |||
373 | /***************************************************************************** |
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374 | Function: |
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375 | void TickUpdate(void) |
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376 | |||
377 | Description: |
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378 | Updates the tick value when an interrupt occurs. |
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379 | |||
380 | Precondition: |
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381 | None |
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382 | |||
383 | Parameters: |
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384 | None |
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385 | |||
386 | Returns: |
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387 | None |
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388 | ***************************************************************************/ |
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389 | #if defined(__18CXX) |
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390 | void TickUpdate(void) |
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391 | { |
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392 | if(INTCONbits.TMR0IF) |
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393 | { |
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394 | // Increment internal high tick counter |
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395 | dwInternalTicks++; |
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396 | |||
397 | // Reset interrupt flag |
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398 | INTCONbits.TMR0IF = 0; |
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399 | } |
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400 | } |
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401 | |||
402 | /***************************************************************************** |
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403 | Function: |
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404 | void _ISR _T1Interrupt(void) |
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405 | |||
406 | Description: |
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407 | Updates the tick value when an interrupt occurs. |
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408 | |||
409 | Precondition: |
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410 | None |
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411 | |||
412 | Parameters: |
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413 | None |
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414 | |||
415 | Returns: |
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416 | None |
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417 | ***************************************************************************/ |
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418 | #elif defined(__PIC32MX__) |
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419 | void __attribute((interrupt(ipl2), vector(_TIMER_1_VECTOR), nomips16)) _T1Interrupt(void) |
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420 | { |
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421 | // Increment internal high tick counter |
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422 | dwInternalTicks++; |
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423 | |||
424 | // Reset interrupt flag |
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425 | IFS0CLR = _IFS0_T1IF_MASK; |
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426 | } |
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427 | #else |
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428 | #if __C30_VERSION__ >= 300 |
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429 | void _ISR __attribute__((__no_auto_psv__)) _T1Interrupt(void) |
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430 | #else |
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431 | void _ISR _T1Interrupt(void) |
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432 | #endif |
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433 | { |
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434 | // Increment internal high tick counter |
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435 | dwInternalTicks++; |
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436 | |||
437 | // Reset interrupt flag |
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438 | IFS0bits.T1IF = 0; |
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439 | } |
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440 | #endif |
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