os_cpu.h

UCOS-III

/*
*********************************************************************************************************
*                                                uC/OS-III
*                                          The Real-Time Kernel
*
*
*                           (c) Copyright 2009-2010; Micrium, Inc.; Weston, FL
*                    All rights reserved.  Protected by international copyright laws.
*
*                                           ARM Cortex-M3 Port
*
* File      : OS_CPU.H
* Version   : V3.01.2
* By        : JJL
*
* LICENSING TERMS:
* ---------------
*             uC/OS-III is provided in source form to registered licensees ONLY.  It is 
*             illegal to distribute this source code to any third party unless you receive 
*             written permission by an authorized Micrium representative.  Knowledge of 
*             the source code may NOT be used to develop a similar product.
*
*             Please help us continue to provide the Embedded community with the finest
*             software available.  Your honesty is greatly appreciated.
*
*             You can contact us at www.micrium.com.
*
* For       : ARMv7M Cortex-M3
* Mode      : Thumb2
* Toolchain : IAR EWARM
*********************************************************************************************************
*/

#ifndef  OS_CPU_H
#define  OS_CPU_H

#ifdef   OS_CPU_GLOBALS
#define  OS_CPU_EXT
#else
#define  OS_CPU_EXT  extern
#endif

/*
*********************************************************************************************************
*                                               MACROS
*********************************************************************************************************
*/

#ifndef  NVIC_INT_CTRL
#define  NVIC_INT_CTRL                      *((CPU_REG32 *)0xE000ED04)
#endif

#ifndef  NVIC_PENDSVSET
#define  NVIC_PENDSVSET                                    0x10000000
#endif

#define  OS_TASK_SW()               NVIC_INT_CTRL = NVIC_PENDSVSET
#define  OSIntCtxSw()               NVIC_INT_CTRL = NVIC_PENDSVSET


/*
*********************************************************************************************************
*                                       TIMESTAMP CONFIGURATION
*
* Note(s) : (1) OS_TS_GET() is generally defined as CPU_TS_Get32() to allow CPU timestamp timer to be of
*               any data type size.
*
*           (2) For architectures that provide 32-bit or higher precision free running counters 
*               (i.e. cycle count registers):
*
*               (a) OS_TS_GET() may be defined as CPU_TS_TmrRd() to improve performance when retrieving
*                   the timestamp.
*
*               (b) CPU_TS_TmrRd() MUST be configured to be greater or equal to 32-bits to avoid
*                   truncation of TS.
*********************************************************************************************************
*/

#if      OS_CFG_TS_EN == 1u
#define  OS_TS_GET()               (CPU_TS)CPU_TS_TmrRd()   /* See Note #2a.                                          */
#else
#define  OS_TS_GET()               (CPU_TS)0u
#endif

#if (CPU_CFG_TS_32_EN    == DEF_ENABLED) && \
    (CPU_CFG_TS_TMR_SIZE  < CPU_WORD_SIZE_32)
                                                            /* CPU_CFG_TS_TMR_SIZE MUST be >= 32-bit (see Note #2b).  */
#error  "cpu_cfg.h, CPU_CFG_TS_TMR_SIZE MUST be >= CPU_WORD_SIZE_32"
#endif


/*
*********************************************************************************************************
*                              OS TICK INTERRUPT PRIORITY CONFIGURATION
*
* Note(s) : (1) For systems that don't need any high, real-time priority interrupts; the tick interrupt
*               should be configured as the highest priority interrupt but won't adversely affect system
*               operations.
*
*           (2) For systems that need one or more high, real-time interrupts; these should be configured
*               higher than the tick interrupt which MAY delay execution of the tick interrupt.
*
*               (a) If the higher priority interrupts do NOT continually consume CPU cycles but only
*                   occasionally delay tick interrupts, then the real-time interrupts can successfully
*                   handle their intermittent/periodic events with the system not losing tick interrupts
*                   but only increasing the jitter.
*
*               (b) If the higher priority interrupts consume enough CPU cycles to continually delay the
*                   tick interrupt, then the CPU/system is most likely over-burdened & can't be expected
*                   to handle all its interrupts/tasks. The system time reference gets compromised as a
*                   result of losing tick interrupts.
*********************************************************************************************************
*/

#define  OS_CPU_CFG_SYSTICK_PRIO           0u

/*
*********************************************************************************************************
*                                          GLOBAL VARIABLES
*********************************************************************************************************
*/

OS_CPU_EXT  CPU_STK  *OS_CPU_ExceptStkBase;

/*
*********************************************************************************************************
*                                         FUNCTION PROTOTYPES
*********************************************************************************************************
*/

void  OSStartHighRdy       (void);

void  OS_CPU_PendSVHandler (void);


void  OS_CPU_SysTickHandler(void);
void  OS_CPU_SysTickInit   (CPU_INT32U  cnts);

#endif