os_cpu.h

UCOSII-2.61源码

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                               实时内核
*
*                        (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
*                                               版权所有
*
*                                            MCU-51 专用代码
*                                           KEIL C51大模式编译
*
* 文件名 : OS_CPU.H
* 作者   : Jean J. Labrosse
* 改编   : 杨屹 [e-mail] 巨龙公司系统集成开发部
*********************************************************************************************************
*/
#ifndef OS_CPU_H
#define OS_CPU_H

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

/*
*********************************************************************************************************
*                                       数据类型
*                                     (编译器相关)
*********************************************************************************************************
*/

//详见C51.PDF第176页
typedef unsigned char  BOOLEAN;       //注意：不要使用bit定义，因为在结构体里无法使用
typedef unsigned char  INT8U;         //无符号8位数
typedef signed   char  INT8S;         //有符号8位数
typedef unsigned int   INT16U;        //无符号16位数
typedef signed   int   INT16S;        //有符号16位数
typedef unsigned long  INT32U;        //无符号32位数
typedef signed   long  INT32S;        //有符号32位数
typedef float          FP32;          //单精度浮点数
typedef double         FP64;          //双精度浮点数

typedef unsigned char  OS_STK;        //栈单元宽度为8比特
typedef unsigned char  OS_CPU_SR;     //51 IE宽度为8bit


#define BYTE           INT8S          //兼容以前版本的数据类型
#define UBYTE          INT8U          //uC/OS-II可以不用这些数据类型
#define WORD           INT16S
#define UWORD          INT16U
#define LONG           INT32S
#define ULONG          INT32U

/* 
*********************************************************************************************************
*                              Intel 80x51 Large Model
*
* 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.
*********************************************************************************************************
*/

#if      OS_CRITICAL_METHOD == 1
#define  OS_ENTER_CRITICAL()  EA=0                          /* Disable interrupts                        */
#define  OS_EXIT_CRITICAL()   EA=1                          /* Enable  interrupts                        */
#endif

#if      OS_CRITICAL_METHOD == 2
#define  OS_ENTER_CRITICAL()                                /* Disable interrupts                        */
#define  OS_EXIT_CRITICAL()                                 /* Enable  interrupts                        */
#endif

#if      OS_CRITICAL_METHOD == 3
#define  OS_ENTER_CRITICAL()    cpu_sr = IE & 0x80; IE &= 0x7F   /* Disable interrupts                   */                    
#define  OS_EXIT_CRITICAL()     IE |= cpu_sr                /* Enable  interrupts                        */
#endif

#define OS_TICKS_PER_SEC                   50               /* Set the number of ticks in one second                        */

#define  OS_STK_GROWTH    0           //MCU-51堆栈从下往上增长  1=向下，0=向上

#define  OS_TASK_SW()     OSCtxSw()   //因为MCU-51没有软中断指令，所以用程序调用代替。两者的堆栈格式相同，
                                      //RETI指令复位中断系统，RET则没有。实践表明，对于MCU-51，用子程序调
                                      //用入栈，用中断返回指令RETI出栈是没有问题的，反之中断入栈RET出栈则
                                      //不行。总之，对于入栈，子程序调用与中断调用效果是一样的，可以混用。
                                      //在没有中断发生的情况下复位中断系统也不会影响系统正常运行。
                                      //详见《uC/OS-II》第八章193页第12行
#endif