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/*
FreeRTOS V7.6.0 - Copyright (C) 2013 Real Time Engineers Ltd.
All rights reserved
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
This file is part of the FreeRTOS distribution.
FreeRTOS is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License (version 2) as published by the
Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
>>! NOTE: The modification to the GPL is included to allow you to distribute
>>! a combined work that includes FreeRTOS without being obliged to provide
>>! the source code for proprietary components outside of the FreeRTOS
>>! kernel.
FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. Full license text is available from the following
link: http://www.freertos.org/a00114.html
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
http://www.FreeRTOS.org - Documentation, books, training, latest versions,
license and Real Time Engineers Ltd. contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool, a DOS
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
http://www.SafeRTOS.com - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
1 tab == 4 spaces!
*/
/*
* This file implements functions to access and manipulate the PIC32 hardware
* without reliance on third party library functions that may be liable to
* change.
*/
/* FreeRTOS includes. */
#include "FreeRTOS.h"
/* Demo includes. */
#include "ConfigPerformance.h"
/* Hardware specific definitions. */
#define hwCHECON_PREFEN_BITS ( 0x03UL << 0x04UL )
#define hwCHECON_WAIT_STAT_BITS ( 0x07UL << 0UL )
#define hwMAX_FLASH_SPEED ( 30000000UL )
#define hwPERIPHERAL_CLOCK_DIV_BY_2 ( 1UL << 0x13UL )
#define hwUNLOCK_KEY_0 ( 0xAA996655UL )
#define hwUNLOCK_KEY_1 ( 0x556699AAUL )
#define hwLOCK_KEY ( 0x33333333UL )
#define hwGLOBAL_INTERRUPT_BIT ( 0x01UL )
#define hwBEV_BIT ( 0x00400000 )
#define hwEXL_BIT ( 0x00000002 )
#define hwIV_BIT ( 0x00800000 )
/*
* Set the flash wait states for the configured CPU clock speed.
*/
static void prvConfigureWaitStates( void );
/*
* Use a divisor of 2 on the peripheral bus.
*/
static void prvConfigurePeripheralBus( void );
/*
* Enable the cache.
*/
static void __attribute__ ((nomips16)) prvKSeg0CacheOn( void );
/*-----------------------------------------------------------*/
void vHardwareConfigurePerformance( void )
{
unsigned long ulStatus;
#ifdef _PCACHE
unsigned long ulCacheStatus;
#endif
/* Disable interrupts - note taskDISABLE_INTERRUPTS() cannot be used here as
FreeRTOS does not globally disable interrupt. */
ulStatus = _CP0_GET_STATUS();
_CP0_SET_STATUS( ulStatus & ~hwGLOBAL_INTERRUPT_BIT );
prvConfigurePeripheralBus();
prvConfigureWaitStates();
/* Disable DRM wait state. */
BMXCONCLR = _BMXCON_BMXWSDRM_MASK;
#ifdef _PCACHE
{
/* Read the current CHECON value. */
ulCacheStatus = CHECON;
/* All the PREFEN bits are being set, so no need to clear first. */
ulCacheStatus |= hwCHECON_PREFEN_BITS;
/* Write back the new value. */
CHECON = ulCacheStatus;
prvKSeg0CacheOn();
}
#endif
/* Reset the status register back to its original value so the original
interrupt enable status is retored. */
_CP0_SET_STATUS( ulStatus );
}
/*-----------------------------------------------------------*/
void vHardwareUseMultiVectoredInterrupts( void )
{
unsigned long ulStatus, ulCause;
extern unsigned long _ebase_address[];
/* Get current status. */
ulStatus = _CP0_GET_STATUS();
/* Disable interrupts. */
ulStatus &= ~hwGLOBAL_INTERRUPT_BIT;
/* Set BEV bit. */
ulStatus |= hwBEV_BIT;
/* Write status back. */
_CP0_SET_STATUS( ulStatus );
/* Setup EBase. */
_CP0_SET_EBASE( ( unsigned long ) _ebase_address );
/* Space vectors by 0x20 bytes. */
_CP0_XCH_INTCTL( 0x20 );
/* Set the IV bit in the CAUSE register. */
ulCause = _CP0_GET_CAUSE();
ulCause |= hwIV_BIT;
_CP0_SET_CAUSE( ulCause );
/* Clear BEV and EXL bits in status. */
ulStatus &= ~( hwBEV_BIT | hwEXL_BIT );
_CP0_SET_STATUS( ulStatus );
/* Set MVEC bit. */
INTCONbits.MVEC = 1;
/* Finally enable interrupts again. */
ulStatus |= hwGLOBAL_INTERRUPT_BIT;
_CP0_SET_STATUS( ulStatus );
}
/*-----------------------------------------------------------*/
static void prvConfigurePeripheralBus( void )
{
unsigned long ulDMAStatus;
__OSCCONbits_t xOSCCONBits;
/* Unlock after suspending. */
ulDMAStatus = DMACONbits.SUSPEND;
if( ulDMAStatus == 0 )
{
DMACONSET = _DMACON_SUSPEND_MASK;
/* Wait until actually suspended. */
while( DMACONbits.SUSPEND == 0 );
}
SYSKEY = 0;
SYSKEY = hwUNLOCK_KEY_0;
SYSKEY = hwUNLOCK_KEY_1;
/* Read to start in sync. */
xOSCCONBits.w = OSCCON;
xOSCCONBits.PBDIV = 0;
xOSCCONBits.w |= hwPERIPHERAL_CLOCK_DIV_BY_2;
/* Write back. */
OSCCON = xOSCCONBits.w;
/* Ensure the write occurred. */
xOSCCONBits.w = OSCCON;
/* Lock again. */
SYSKEY = hwLOCK_KEY;
/* Resume DMA activity. */
if( ulDMAStatus == 0 )
{
DMACONCLR=_DMACON_SUSPEND_MASK;
}
}
/*-----------------------------------------------------------*/
static void prvConfigureWaitStates( void )
{
unsigned long ulSystemClock = configCPU_CLOCK_HZ - 1;
unsigned long ulWaitStates, ulCHECONVal;
/* 1 wait state for every hwMAX_FLASH_SPEED MHz. */
ulWaitStates = 0;
while( ulSystemClock > hwMAX_FLASH_SPEED )
{
ulWaitStates++;
ulSystemClock -= hwMAX_FLASH_SPEED;
}
/* Obtain current CHECON value. */
ulCHECONVal = CHECON;
/* Clear the wait state bits, then set the calculated wait state bits. */
ulCHECONVal &= ~hwCHECON_WAIT_STAT_BITS;
ulCHECONVal |= ulWaitStates;
/* Write back the new value. */
CHECON = ulWaitStates;
}
/*-----------------------------------------------------------*/
static void __attribute__ ((nomips16)) prvKSeg0CacheOn( void )
{
unsigned long ulValue;
__asm volatile( "mfc0 %0, $16, 0" : "=r"( ulValue ) );
ulValue = ( ulValue & ~0x07) | 0x03;
__asm volatile( "mtc0 %0, $16, 0" :: "r" ( ulValue ) );
}
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