驱动编程的小问题

yangdong5800 · 发表于 2012-4-12 20:05:42

   你们好，我是学习STM32F10X的新手，在读使用C语言编程的驱动初始化时，老是碰到一些小问题。请求各位高手的指教。
比如在STM32F10X_NVIC.C文件中，有一个设置优先级分组的函数：
/******************************************************
* Function Name : NVIC_PriorityGroupConfig
* Description    : Configures the priority grouping: pre-emption priority
*                      and subpriority.
* input:            - NVIC_PriorityGroup: specifies the priority grouping bits
*                       length. This parameter can be one of the following values:
*                       - NVIC_PriorityGroup_0: 0 bits for pre-emption priority
*                         4 bits for subpriority
*                       - NVIC_PriorityGroup_1: 1 bits for pre-emption priority
*                         3 bits for subpriority
*                       - NVIC_PriorityGroup_2: 2 bits for pre-emption priority
*                         2 bits for subpriority
*                       - NVIC_PriorityGroup_3: 3 bits for pre-emption priority
*                         1 bits for subpriority
*                       - NVIC_PriorityGroup_4: 4 bits for pre-emption priority
*                         0 bits for subpriority
* Output         : None
* Return          : None
*******************************************************************************/
void NVIC_PriorityGroupConfig(u32 NVIC_PriorityGroup)
{
/* Check the parameters */
assert_param(IS_NVIC_PRIORITY_GROUP(NVIC_PriorityGroup));

/* Set the PRIGROUP[10:8] bits according to NVIC_PriorityGroup value */
SCB->AIRCR = AIRCR_VECTKEY_MASK | NVIC_PriorityGroup;
}
说明中的prigroup[10:8]bits 是什么意思？