32位 的变量 用于表示 ms ,可以表示多少天那？

1、在  TI  的 BLE 协议栈 中，即 OSAL 中 获取当前 系统 tick 的方法如下

 /*
  * Read the system clock - returns milliseconds
  */
  extern uint32 osal_GetSystemClock( void );

2、32位 的变量 用于表示 ms ,可以表示多少天那？关系如下：

2^32 ms = 

4294967296 ms =

4294967.296 S = 

71582.788266666666666666666666667 分钟 = 

1193.0464711111111111111111111111 小时 = 

49.71026962962962962962962962963 天

/******************************************************************************

 @file  OSAL_Timers.h

 @brief This file contains the OSAL Timer definition and manipulation functions.

 Group: WCS, BTS
 Target Device: CC2540, CC2541

 ******************************************************************************
 
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 ******************************************************************************
 Release Name: ble_sdk_1.4.2.2
 Release Date: 2016-06-09 06:57:09
 *****************************************************************************/

#ifndef OSAL_TIMERS_H
#define OSAL_TIMERS_H

#ifdef __cplusplus
extern "C"
{
#endif

/*********************************************************************
 * INCLUDES
 */

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

/*********************************************************************
 * CONSTANTS
 * the unit is chosen such that the 320us tick equivalent can fit in 
 * 32 bits.
 */
 #define OSAL_TIMERS_MAX_TIMEOUT 0x28f5c28e /* unit is ms*/

/*********************************************************************
 * TYPEDEFS
 */

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

/*********************************************************************
 * FUNCTIONS
 */

  /*
   * Initialization for the OSAL Timer System.
   */
  extern void osalTimerInit( void );

  /*
   * Set a Timer
   */
  extern uint8 osal_start_timerEx( uint8 task_id, uint16 event_id, uint32 timeout_value );
  
  /*
   * Set a timer that reloads itself.
   */
  extern uint8 osal_start_reload_timer( uint8 taskID, uint16 event_id, uint32 timeout_value );

  /*
   * Stop a Timer
   */
  extern uint8 osal_stop_timerEx( uint8 task_id, uint16 event_id );

  /*
   * Get the tick count of a Timer.
   */
  extern uint32 osal_get_timeoutEx( uint8 task_id, uint16 event_id );

  /*
   * Simulated Timer Interrupt Service Routine
   */

  extern void osal_timer_ISR( void );

  /*
   * Adjust timer tables
   */
  extern void osal_adjust_timers( void );

  /*
   * Update timer tables
   */
  extern void osalTimerUpdate( uint32 updateTime );

  /*
   * Count active timers
   */
  extern uint8 osal_timer_num_active( void );

  /*
   * Set the hardware timer interrupts for sleep mode.
   * These functions should only be called in OSAL_PwrMgr.c
   */
  extern void osal_sleep_timers( void );
  extern void osal_unsleep_timers( void );

 /*
  * Read the system clock - returns milliseconds
  */
  extern uint32 osal_GetSystemClock( void );

  /*
   * Get the next OSAL timer expiration.
   * This function should only be called in OSAL_PwrMgr.c
   */
  extern uint32 osal_next_timeout( void );

/*********************************************************************
*********************************************************************/

#ifdef __cplusplus
}
#endif

#endif /* OSAL_TIMERS_H */