2 FreeRTOS V7.6.0 - Copyright (C) 2013 Real Time Engineers Ltd.
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5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS provides completely free yet professionally developed, *
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10 * robust, strictly quality controlled, supported, and cross *
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11 * platform software that has become a de facto standard. *
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13 * Help yourself get started quickly and support the FreeRTOS *
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14 * project by purchasing a FreeRTOS tutorial book, reference *
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15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
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19 ***************************************************************************
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21 This file is part of the FreeRTOS distribution.
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23 FreeRTOS is free software; you can redistribute it and/or modify it under
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24 the terms of the GNU General Public License (version 2) as published by the
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25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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27 >>! NOTE: The modification to the GPL is included to allow you to distribute
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28 >>! a combined work that includes FreeRTOS without being obliged to provide
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29 >>! the source code for proprietary components outside of the FreeRTOS
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32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
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35 link: http://www.freertos.org/a00114.html
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39 ***************************************************************************
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41 * Having a problem? Start by reading the FAQ "My application does *
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42 * not run, what could be wrong?" *
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44 * http://www.FreeRTOS.org/FAQHelp.html *
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46 ***************************************************************************
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48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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49 license and Real Time Engineers Ltd. contact details.
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51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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57 licenses offer ticketed support, indemnification and middleware.
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59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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60 engineered and independently SIL3 certified version for use in safety and
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61 mission critical applications that require provable dependability.
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66 /*-----------------------------------------------------------
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67 * Implementation of functions defined in portable.h for the RX100 port.
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68 *----------------------------------------------------------*/
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70 /* Standard C includes. */
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73 /* Scheduler includes. */
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74 #include "FreeRTOS.h"
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77 /* Library includes. */
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80 /* Hardware specifics. */
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81 #include "iodefine.h"
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83 /*-----------------------------------------------------------*/
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85 /* Tasks should start with interrupts enabled and in Supervisor mode, therefore
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86 PSW is set with U and I set, and PM and IPL clear. */
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87 #define portINITIAL_PSW ( ( StackType_t ) 0x00030000 )
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89 /* The peripheral clock is divided by this value before being supplying the
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91 #if ( configUSE_TICKLESS_IDLE == 0 )
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92 /* If tickless idle is not used then the divisor can be fixed. */
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93 #define portCLOCK_DIVISOR 8UL
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94 #elif ( configPERIPHERAL_CLOCK_HZ >= 12000000 )
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95 #define portCLOCK_DIVISOR 512UL
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96 #elif ( configPERIPHERAL_CLOCK_HZ >= 6000000 )
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97 #define portCLOCK_DIVISOR 128UL
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98 #elif ( configPERIPHERAL_CLOCK_HZ >= 1000000 )
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99 #define portCLOCK_DIVISOR 32UL
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101 #define portCLOCK_DIVISOR 8UL
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105 /* Keys required to lock and unlock access to certain system registers
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107 #define portUNLOCK_KEY 0xA50B
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108 #define portLOCK_KEY 0xA500
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110 /*-----------------------------------------------------------*/
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112 /* The following lines are to ensure vSoftwareInterruptEntry can be referenced,
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113 and therefore installed in the vector table, when the FreeRTOS code is built
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115 extern BaseType_t vSoftwareInterruptEntry;
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116 const BaseType_t * p_vSoftwareInterruptEntry = &vSoftwareInterruptEntry;
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118 /*-----------------------------------------------------------*/
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121 * Function to start the first task executing - written in asm code as direct
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122 * access to registers is required.
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124 static void prvStartFirstTask( void );
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127 * Software interrupt handler. Performs the actual context switch (saving and
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128 * restoring of registers). Written in asm code as direct register access is
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131 static void prvYieldHandler( void );
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134 * The entry point for the software interrupt handler. This is the function
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135 * that calls the inline asm function prvYieldHandler(). It is installed in
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136 * the vector table, but the code that installs it is in prvYieldHandler rather
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137 * than using a #pragma.
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139 void vSoftwareInterruptISR( void );
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142 * Sets up the periodic ISR used for the RTOS tick using the CMT.
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143 * The application writer can define configSETUP_TICK_INTERRUPT() (in
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144 * FreeRTOSConfig.h) such that their own tick interrupt configuration is used
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145 * in place of prvSetupTimerInterrupt().
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147 static void prvSetupTimerInterrupt( void );
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148 #ifndef configSETUP_TICK_INTERRUPT
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149 /* The user has not provided their own tick interrupt configuration so use
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150 the definition in this file (which uses the interval timer). */
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151 #define configSETUP_TICK_INTERRUPT() prvSetupTimerInterrupt()
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152 #endif /* configSETUP_TICK_INTERRUPT */
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155 * Called after the sleep mode registers have been configured, prvSleep()
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156 * executes the pre and post sleep macros, and actually calls the wait
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159 #if configUSE_TICKLESS_IDLE == 1
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160 static void prvSleep( TickType_t xExpectedIdleTime );
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161 #endif /* configUSE_TICKLESS_IDLE */
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163 /*-----------------------------------------------------------*/
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165 /* These is accessed by the inline assembler functions. */
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166 extern void *pxCurrentTCB;
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167 extern void vTaskSwitchContext( void );
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169 /*-----------------------------------------------------------*/
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171 /* Calculate how many clock increments make up a single tick period. */
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172 static const uint32_t ulMatchValueForOneTick = ( ( configPERIPHERAL_CLOCK_HZ / portCLOCK_DIVISOR ) / configTICK_RATE_HZ );
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174 #if configUSE_TICKLESS_IDLE == 1
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176 /* Holds the maximum number of ticks that can be suppressed - which is
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177 basically how far into the future an interrupt can be generated. Set
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178 during initialisation. This is the maximum possible value that the
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179 compare match register can hold divided by ulMatchValueForOneTick. */
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180 static const TickType_t xMaximumPossibleSuppressedTicks = USHRT_MAX / ( ( configPERIPHERAL_CLOCK_HZ / portCLOCK_DIVISOR ) / configTICK_RATE_HZ );
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182 /* Flag set from the tick interrupt to allow the sleep processing to know if
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183 sleep mode was exited because of a tick interrupt, or an interrupt
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184 generated by something else. */
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185 static volatile uint32_t ulTickFlag = pdFALSE;
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187 /* The CMT counter is stopped temporarily each time it is re-programmed.
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188 The following constant offsets the CMT counter match value by the number of
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189 CMT counts that would typically be missed while the counter was stopped to
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190 compensate for the lost time. The large difference between the divided CMT
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191 clock and the CPU clock means it is likely ulStoppedTimerCompensation will
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192 equal zero - and be optimised away. */
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193 static const uint32_t ulStoppedTimerCompensation = 100UL / ( configCPU_CLOCK_HZ / ( configPERIPHERAL_CLOCK_HZ / portCLOCK_DIVISOR ) );
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197 /*-----------------------------------------------------------*/
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200 * See header file for description.
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202 StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
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204 /* Offset to end up on 8 byte boundary. */
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207 /* R0 is not included as it is the stack pointer. */
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208 *pxTopOfStack = 0x00;
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210 *pxTopOfStack = 0x00;
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212 *pxTopOfStack = portINITIAL_PSW;
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214 *pxTopOfStack = ( StackType_t ) pxCode;
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216 /* When debugging it can be useful if every register is set to a known
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217 value. Otherwise code space can be saved by just setting the registers
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218 that need to be set. */
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219 #ifdef USE_FULL_REGISTER_INITIALISATION
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222 *pxTopOfStack = 0x12345678; /* r15. */
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224 *pxTopOfStack = 0xaaaabbbb;
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226 *pxTopOfStack = 0xdddddddd;
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228 *pxTopOfStack = 0xcccccccc;
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230 *pxTopOfStack = 0xbbbbbbbb;
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232 *pxTopOfStack = 0xaaaaaaaa;
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234 *pxTopOfStack = 0x99999999;
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236 *pxTopOfStack = 0x88888888;
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238 *pxTopOfStack = 0x77777777;
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240 *pxTopOfStack = 0x66666666;
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242 *pxTopOfStack = 0x55555555;
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244 *pxTopOfStack = 0x44444444;
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246 *pxTopOfStack = 0x33333333;
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248 *pxTopOfStack = 0x22222222;
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253 /* Leave space for the registers that will get popped from the stack
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254 when the task first starts executing. */
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255 pxTopOfStack -= 15;
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259 *pxTopOfStack = ( StackType_t ) pvParameters; /* R1 */
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261 *pxTopOfStack = 0x12345678; /* Accumulator. */
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263 *pxTopOfStack = 0x87654321; /* Accumulator. */
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265 return pxTopOfStack;
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267 /*-----------------------------------------------------------*/
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269 BaseType_t xPortStartScheduler( void )
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271 /* Use pxCurrentTCB just so it does not get optimised away. */
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272 if( pxCurrentTCB != NULL )
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274 /* Call an application function to set up the timer that will generate
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275 the tick interrupt. This way the application can decide which
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276 peripheral to use. If tickless mode is used then the default
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277 implementation defined in this file (which uses CMT0) should not be
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279 configSETUP_TICK_INTERRUPT();
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281 /* Enable the software interrupt. */
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282 _IEN( _ICU_SWINT ) = 1;
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284 /* Ensure the software interrupt is clear. */
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285 _IR( _ICU_SWINT ) = 0;
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287 /* Ensure the software interrupt is set to the kernel priority. */
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288 _IPR( _ICU_SWINT ) = configKERNEL_INTERRUPT_PRIORITY;
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290 /* Start the first task. */
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291 prvStartFirstTask();
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294 /* Execution should not reach here as the tasks are now running!
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295 prvSetupTimerInterrupt() is called here to prevent the compiler outputting
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296 a warning about a statically declared function not being referenced in the
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297 case that the application writer has provided their own tick interrupt
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298 configuration routine (and defined configSETUP_TICK_INTERRUPT() such that
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299 their own routine will be called in place of prvSetupTimerInterrupt()). */
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300 prvSetupTimerInterrupt();
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302 /* Just to make sure the function is not optimised away. */
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303 ( void ) vSoftwareInterruptISR();
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305 /* Should not get here. */
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308 /*-----------------------------------------------------------*/
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310 #pragma inline_asm prvStartFirstTask
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311 static void prvStartFirstTask( void )
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313 /* When starting the scheduler there is nothing that needs moving to the
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314 interrupt stack because the function is not called from an interrupt.
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315 Just ensure the current stack is the user stack. */
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318 /* Obtain the location of the stack associated with which ever task
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319 pxCurrentTCB is currently pointing to. */
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320 MOV.L #_pxCurrentTCB, R15
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324 /* Restore the registers from the stack of the task pointed to by
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327 MVTACLO R15 /* Accumulator low 32 bits. */
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329 MVTACHI R15 /* Accumulator high 32 bits. */
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330 POPM R1-R15 /* R1 to R15 - R0 is not included as it is the SP. */
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331 RTE /* This pops the remaining registers. */
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335 /*-----------------------------------------------------------*/
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337 #pragma interrupt ( prvTickISR( vect = configTICK_VECTOR, enable ) )
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338 void prvTickISR( void )
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340 /* Increment the tick, and perform any processing the new tick value
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342 set_ipl( configMAX_SYSCALL_INTERRUPT_PRIORITY );
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344 if( xTaskIncrementTick() != pdFALSE )
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349 set_ipl( configKERNEL_INTERRUPT_PRIORITY );
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351 #if configUSE_TICKLESS_IDLE == 1
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353 /* The CPU woke because of a tick. */
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354 ulTickFlag = pdTRUE;
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356 /* If this is the first tick since exiting tickless mode then the CMT
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357 compare match value needs resetting. */
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358 CMT0.CMCOR = ( uint16_t ) ulMatchValueForOneTick;
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362 /*-----------------------------------------------------------*/
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364 void vSoftwareInterruptISR( void )
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368 /*-----------------------------------------------------------*/
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370 #pragma inline_asm prvYieldHandler
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371 static void prvYieldHandler( void )
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373 /* Re-enable interrupts. */
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376 /* Move the data that was automatically pushed onto the interrupt stack
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377 when the interrupt occurred from the interrupt stack to the user stack.
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379 R15 is saved before it is clobbered. */
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382 /* Read the user stack pointer. */
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385 /* Move the address down to the data being moved. */
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389 /* Copy the data across. */
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390 MOV.L [ R0 ], [ R15 ] ; R15
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391 MOV.L 4[ R0 ], 4[ R15 ] ; PC
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392 MOV.L 8[ R0 ], 8[ R15 ] ; PSW
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394 /* Move the interrupt stack pointer to its new correct position. */
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397 /* All the rest of the registers are saved directly to the user stack. */
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400 /* Save the rest of the general registers (R15 has been saved already). */
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403 /* Save the accumulator. */
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406 MVFACMI R15 ; Middle order word.
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407 SHLL #16, R15 ; Shifted left as it is restored to the low order word.
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410 /* Save the stack pointer to the TCB. */
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411 MOV.L #_pxCurrentTCB, R15
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415 /* Ensure the interrupt mask is set to the syscall priority while the
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416 kernel structures are being accessed. */
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417 MVTIPL #configMAX_SYSCALL_INTERRUPT_PRIORITY
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419 /* Select the next task to run. */
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420 BSR.A _vTaskSwitchContext
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422 /* Reset the interrupt mask as no more data structure access is
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424 MVTIPL #configKERNEL_INTERRUPT_PRIORITY
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426 /* Load the stack pointer of the task that is now selected as the Running
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427 state task from its TCB. */
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428 MOV.L #_pxCurrentTCB,R15
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432 /* Restore the context of the new task. The PSW (Program Status Word) and
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433 PC will be popped by the RTE instruction. */
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443 /*-----------------------------------------------------------*/
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445 void vPortEndScheduler( void )
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447 /* Not implemented in ports where there is nothing to return to.
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448 Artificially force an assert. */
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449 configASSERT( pxCurrentTCB == NULL );
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451 /* The following line is just to prevent the symbol getting optimised away. */
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452 ( void ) vTaskSwitchContext();
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454 /*-----------------------------------------------------------*/
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456 static void prvSetupTimerInterrupt( void )
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459 SYSTEM.PRCR.WORD = portUNLOCK_KEY;
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465 SYSTEM.PRCR.WORD = portLOCK_KEY;
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467 /* Interrupt on compare match. */
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468 CMT0.CMCR.BIT.CMIE = 1;
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470 /* Set the compare match value. */
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471 CMT0.CMCOR = ( uint16_t ) ulMatchValueForOneTick;
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473 /* Divide the PCLK. */
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474 #if portCLOCK_DIVISOR == 512
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476 CMT0.CMCR.BIT.CKS = 3;
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478 #elif portCLOCK_DIVISOR == 128
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480 CMT0.CMCR.BIT.CKS = 2;
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482 #elif portCLOCK_DIVISOR == 32
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484 CMT0.CMCR.BIT.CKS = 1;
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486 #elif portCLOCK_DIVISOR == 8
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488 CMT0.CMCR.BIT.CKS = 0;
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492 #error Invalid portCLOCK_DIVISOR setting
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497 /* Enable the interrupt... */
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498 _IEN( _CMT0_CMI0 ) = 1;
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500 /* ...and set its priority to the application defined kernel priority. */
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501 _IPR( _CMT0_CMI0 ) = configKERNEL_INTERRUPT_PRIORITY;
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503 /* Start the timer. */
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504 CMT.CMSTR0.BIT.STR0 = 1;
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506 /*-----------------------------------------------------------*/
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508 #if configUSE_TICKLESS_IDLE == 1
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510 static void prvSleep( TickType_t xExpectedIdleTime )
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512 /* Allow the application to define some pre-sleep processing. */
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513 configPRE_SLEEP_PROCESSING( xExpectedIdleTime );
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515 /* xExpectedIdleTime being set to 0 by configPRE_SLEEP_PROCESSING()
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516 means the application defined code has already executed the WAIT
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518 if( xExpectedIdleTime > 0 )
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523 /* Allow the application to define some post sleep processing. */
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524 configPOST_SLEEP_PROCESSING( xExpectedIdleTime );
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527 #endif /* configUSE_TICKLESS_IDLE */
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528 /*-----------------------------------------------------------*/
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530 #if configUSE_TICKLESS_IDLE == 1
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532 void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )
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534 uint32_t ulMatchValue, ulCompleteTickPeriods, ulCurrentCount;
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535 eSleepModeStatus eSleepAction;
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537 /* THIS FUNCTION IS CALLED WITH THE SCHEDULER SUSPENDED. */
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539 /* Make sure the CMT reload value does not overflow the counter. */
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540 if( xExpectedIdleTime > xMaximumPossibleSuppressedTicks )
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542 xExpectedIdleTime = xMaximumPossibleSuppressedTicks;
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545 /* Calculate the reload value required to wait xExpectedIdleTime tick
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547 ulMatchValue = ulMatchValueForOneTick * xExpectedIdleTime;
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548 if( ulMatchValue > ulStoppedTimerCompensation )
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550 /* Compensate for the fact that the CMT is going to be stopped
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552 ulMatchValue -= ulStoppedTimerCompensation;
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555 /* Stop the CMT momentarily. The time the CMT is stopped for is
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556 accounted for as best it can be, but using the tickless mode will
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557 inevitably result in some tiny drift of the time maintained by the
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558 kernel with respect to calendar time. */
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559 CMT.CMSTR0.BIT.STR0 = 0;
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560 while( CMT.CMSTR0.BIT.STR0 == 1 )
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562 /* Nothing to do here. */
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565 /* Critical section using the global interrupt bit as the i bit is
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566 automatically reset by the WAIT instruction. */
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569 /* The tick flag is set to false before sleeping. If it is true when
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570 sleep mode is exited then sleep mode was probably exited because the
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571 tick was suppressed for the entire xExpectedIdleTime period. */
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572 ulTickFlag = pdFALSE;
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574 /* If a context switch is pending then abandon the low power entry as
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575 the context switch might have been pended by an external interrupt that
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576 requires processing. */
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577 eSleepAction = eTaskConfirmSleepModeStatus();
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578 if( eSleepAction == eAbortSleep )
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580 /* Restart tick. */
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581 CMT.CMSTR0.BIT.STR0 = 1;
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584 else if( eSleepAction == eNoTasksWaitingTimeout )
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586 /* Protection off. */
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587 SYSTEM.PRCR.WORD = portUNLOCK_KEY;
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589 /* Ready for software standby with all clocks stopped. */
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590 SYSTEM.SBYCR.BIT.SSBY = 1;
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592 /* Protection on. */
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593 SYSTEM.PRCR.WORD = portLOCK_KEY;
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595 /* Sleep until something happens. Calling prvSleep() will
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596 automatically reset the i bit in the PSW. */
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597 prvSleep( xExpectedIdleTime );
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599 /* Restart the CMT. */
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600 CMT.CMSTR0.BIT.STR0 = 1;
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604 /* Protection off. */
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605 SYSTEM.PRCR.WORD = portUNLOCK_KEY;
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607 /* Ready for deep sleep mode. */
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608 SYSTEM.MSTPCRC.BIT.DSLPE = 1;
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609 SYSTEM.MSTPCRA.BIT.MSTPA28 = 1;
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610 SYSTEM.SBYCR.BIT.SSBY = 0;
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612 /* Protection on. */
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613 SYSTEM.PRCR.WORD = portLOCK_KEY;
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615 /* Adjust the match value to take into account that the current
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616 time slice is already partially complete. */
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617 ulMatchValue -= ( uint32_t ) CMT0.CMCNT;
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618 CMT0.CMCOR = ( uint16_t ) ulMatchValue;
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620 /* Restart the CMT to count up to the new match value. */
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622 CMT.CMSTR0.BIT.STR0 = 1;
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624 /* Sleep until something happens. Calling prvSleep() will
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625 automatically reset the i bit in the PSW. */
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626 prvSleep( xExpectedIdleTime );
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628 /* Stop CMT. Again, the time the SysTick is stopped for is
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629 accounted for as best it can be, but using the tickless mode will
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630 inevitably result in some tiny drift of the time maintained by the
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631 kernel with respect to calendar time. */
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632 CMT.CMSTR0.BIT.STR0 = 0;
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633 while( CMT.CMSTR0.BIT.STR0 == 1 )
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635 /* Nothing to do here. */
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638 ulCurrentCount = ( uint32_t ) CMT0.CMCNT;
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640 if( ulTickFlag != pdFALSE )
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642 /* The tick interrupt has already executed, although because
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643 this function is called with the scheduler suspended the actual
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644 tick processing will not occur until after this function has
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645 exited. Reset the match value with whatever remains of this
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647 ulMatchValue = ulMatchValueForOneTick - ulCurrentCount;
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648 CMT0.CMCOR = ( uint16_t ) ulMatchValue;
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650 /* The tick interrupt handler will already have pended the tick
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651 processing in the kernel. As the pending tick will be
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652 processed as soon as this function exits, the tick value
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653 maintained by the tick is stepped forward by one less than the
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654 time spent sleeping. The actual stepping of the tick appears
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655 later in this function. */
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656 ulCompleteTickPeriods = xExpectedIdleTime - 1UL;
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660 /* Something other than the tick interrupt ended the sleep.
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661 How many complete tick periods passed while the processor was
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663 ulCompleteTickPeriods = ulCurrentCount / ulMatchValueForOneTick;
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665 /* The match value is set to whatever fraction of a single tick
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667 ulMatchValue = ulCurrentCount - ( ulCompleteTickPeriods * ulMatchValueForOneTick );
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668 CMT0.CMCOR = ( uint16_t ) ulMatchValue;
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671 /* Restart the CMT so it runs up to the match value. The match value
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672 will get set to the value required to generate exactly one tick period
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673 the next time the CMT interrupt executes. */
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675 CMT.CMSTR0.BIT.STR0 = 1;
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677 /* Wind the tick forward by the number of tick periods that the CPU
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678 remained in a low power state. */
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679 vTaskStepTick( ulCompleteTickPeriods );
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683 #endif /* configUSE_TICKLESS_IDLE */
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