os_cpu.h

uCOS-II example for MC9S12DPxxx

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                         (c) Copyright 2002, Jean J. Labrosse, Weston, FL
*                                          All Rights Reserved
*
*
*                                          MC9S12 Specific Code
*                                        Freescale Serial Monitor         
*                                           Banked Memory Model     
*                                             Codewarrior 4.x 
*
* File         : OS_CPU.H
* By           : Eric Shufro
* Port Version : V2.83 and higher
*
* Note(s)      : (1) This port will not function in expanded mode. This is due to the fact that the 
*                    OS_TASK_SW() macro utilizes JSR instead of CALL.  The CALL instruction may not
*                    be used in place of JSR since it pushes the PPAGE register on the stack which 
*                    will corrupts the stack frame. JSR only pushes the PC on to the stack which
*                    is compatible the MC9S12 ISR exception stack handling procedures (see RTI).
*
*                (2) This port utilizes JSR instead of SWI when performing a task level context switch
*                    due to the fact that the Freescale MC9S12 Serial Monitor utilizes the SWI trap
*                    for break points.
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*                                              DATA TYPES
*********************************************************************************************************
*/

void  OSCtxSw(void);


/*
*********************************************************************************************************
*                                              DATA TYPES
*********************************************************************************************************
*/

typedef unsigned char  BOOLEAN;
typedef unsigned char  INT8U;                    /* Unsigned  8 bit quantity                           */
typedef signed   char  INT8S;                    /* Signed    8 bit quantity                           */
typedef unsigned int   INT16U;                   /* Unsigned 16 bit quantity                           */
typedef signed   int   INT16S;                   /* Signed   16 bit quantity                           */
typedef unsigned long  INT32U;                   /* Unsigned 32 bit quantity                           */
typedef signed   long  INT32S;                   /* Signed   32 bit quantity                           */
typedef float          FP32;                     /* Single precision floating point                    */
typedef double         FP64;                     /* Double precision floating point                    */

#define BYTE           INT8S                     /* Define data types for backward compatibility ...   */
#define UBYTE          INT8U                     /* ... to uC/OS V1.xx                                 */
#define WORD           INT16S
#define UWORD          INT16U
#define LONG           INT32S
#define ULONG          INT32U

typedef unsigned char  OS_STK;                   /* Each stack entry is 8-bit wide                     */
typedef unsigned char  OS_CPU_SR;                /* Define size of CPU status register (PSW = 16 bits) */


/*
*********************************************************************************************************
*                                              CONSTANTS
*********************************************************************************************************
*/

#ifndef  FALSE
#define  FALSE    0
#endif

#ifndef  TRUE
#define  TRUE     1
#endif


/* 
*********************************************************************************************************
*                                           Motorola 68HC12
*
* Method #1:  Disable/Enable interrupts using simple instructions.  After critical section, interrupts
*             will be enabled even if they were disabled before entering the critical section.
*
* Method #2:  Disable/Enable interrupts by preserving the state of interrupts.  In other words, if 
*             interrupts were disabled before entering the critical section, they will be disabled when
*             leaving the critical section.
*
* Method #3:  Disable/Enable interrupts by preserving the state of interrupts.  Generally speaking you
*             would store the state of the interrupt disable flag in the local variable 'cpu_sr' and then
*             disable interrupts.  'cpu_sr' is allocated in all of uC/OS-II's functions that need to 
*             disable interrupts.  You would restore the interrupt disable state by copying back 'cpu_sr'
*             into the CPU's status register.
*
* NOTE(s)  :  1) The current version of the compiler does NOT allow method #2 to be used without changing
*                the processor independent portion of uC/OS-II.
*             2) The current version of the compiler does NOT allow method #3 either.  However, this can
*                be implemented in OS_CPU_A.S by defining the functions: OSCPUSaveSR() and 
*                OSCPURestoreSR().
*********************************************************************************************************
*/

#define  OS_CRITICAL_METHOD    3


#if      OS_CRITICAL_METHOD == 3
#define  OS_ENTER_CRITICAL()  cpu_sr = OS_CPU_SR_Save()             /* Disable interrupts              */
#define  OS_EXIT_CRITICAL()   OS_CPU_SR_Restore(cpu_sr)             /* Enable  interrupts              */
#endif


#define  OS_TASK_SW()         asm "jsr OSCtxSw"
    
    
                                                                    /* banked, mode this macro creates */
                                                                    /* code for "call OSCtxSw"         */
		 			 	   
#define  OS_STK_GROWTH        1                                     /* Stack growth: 1 = Down, 0 = Up  */


/*
*********************************************************************************************************
*                                 REDEFINE THE PROTOTYPES FOR THE ISRs
*********************************************************************************************************
*/

OS_CPU_SR  OS_CPU_SR_Save(void);
void       OS_CPU_SR_Restore(OS_CPU_SR cpu_sr);
void       OSTickISRHandler(void);