飞思卡尔MCU自定义中断向量的相关问题 bootloader程序过程中的问题

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中断服务代码前必须要声明

#pragma CODE_SEG __NEAR_SEG NON_BANKED

这样编译器产生的指针（向量）为16bit长。如果不加"NON_BANKED"声明，缺省代码指针为24bit长（为代码段分页考虑），这样向量表的一个单元就不能容纳。

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自定义中断向量的情况说明

#pragma CODE_SEG NON_BANKED
// 声明外部中断函数
extern void Timer0_C0(void);
extern void _Startup(void); //Startup routine */

#pragma CODE_SEG NON_BANKED
/* Interrupt section for this module. Placement will be in NON_BANKED area. */
__interrupt void UnimplementedISR(void) //定义在NON_BANKED区
{
asm BGND; //空的中断函数
}
typedef void (*near tIsrFunc)(void); //定义了函数指针类型

//定义一个函数指针数组中断表，从0xFF80地址开始装载各个中断函数的首地址
const tIsrFunc _vect[] @0xFF80 = /* Interrupt table */
{
UnimplementedISR, /* vector 63 */
UnimplementedISR, /* vector 62 */
UnimplementedISR, /* vector 61 */
UnimplementedISR, /* vector 60 */
UnimplementedISR, /* vector 59 */
UnimplementedISR, /* vector 58 */
UnimplementedISR, /* vector 57 */
UnimplementedISR, /* vector 56 */
UnimplementedISR, /* vector 55 */
UnimplementedISR, /* vector 54 */
UnimplementedISR, /* vector 53 */
UnimplementedISR, /* vector 52 */
UnimplementedISR, /* vector 51 */
UnimplementedISR, /* vector 50 */
UnimplementedISR, /* vector 49 */
UnimplementedISR, /* vector 48 */
UnimplementedISR, /* vector 47 */
UnimplementedISR, /* vector 46 */
UnimplementedISR, /* vector 45 */
UnimplementedISR, /* vector 44 */
UnimplementedISR, /* vector 43 */
UnimplementedISR, /* vector 42 */
UnimplementedISR, /* vector 41 */
UnimplementedISR, /* vector 40 */
UnimplementedISR, /* vector 39 */
UnimplementedISR, /* vector 38 */
UnimplementedISR, /* vector 37 */
UnimplementedISR, /* vector 36 */
UnimplementedISR, /* vector 35 */
UnimplementedISR, /* vector 34 */
UnimplementedISR, /* vector 33 */
UnimplementedISR, /* vector 32 */
UnimplementedISR, /* vector 31 */
UnimplementedISR, /* vector 30 */
UnimplementedISR, /* vector 29 */
UnimplementedISR, /* vector 28 */
UnimplementedISR, /* vector 27 */
UnimplementedISR, /* vector 26 */
UnimplementedISR, /* vector 25 */
UnimplementedISR, /* vector 24 */
UnimplementedISR, /* vector 23 */
UnimplementedISR, /* vector 22 */
UnimplementedISR, /* vector 21 */
UnimplementedISR, /* vector 20 */
UnimplementedISR, /* vector 19 */
UnimplementedISR, /* vector 18 */
UnimplementedISR, /* vector 17 */
UnimplementedISR, /* vector 16 */
UnimplementedISR, /* vector 15 */
UnimplementedISR, /* vector 14 */
UnimplementedISR, /* vector 13 */
UnimplementedISR, /* vector 12 */
UnimplementedISR, /* vector 11 */
UnimplementedISR, /* vector 10 */
UnimplementedISR, /* vector 09 */
Timer0_C0, /* vector 08 */
UnimplementedISR, /* vector 07 */
UnimplementedISR, /* vector 06 */
UnimplementedISR, /* vector 05 */
UnimplementedISR, /* vector 04 */
UnimplementedISR, /* vector 03 */
UnimplementedISR, /* vector 02 */
UnimplementedISR, /* vector 01 */
_Startup /* Reset vector */
};
在编译的时候，假如出现以下的错误提示
ERROR: Vector allocated at absolute address 0xFFFE overlaps with sections placed in segment xxxx
则说明_Startup()函数的绝对地址约束存在二义性。
可以直接打开对应工程文件的PRM文件，将最后的 “VECTOR 0 _Startup ”注释掉。
因为这句话的意思就是值，将_Startup 函数放在 0号中断向量的地方。
而上面我们自己定义的_vect[]表，的最后一个也是_Startup（）函数，并且制定了绝对地址。如此一来就和VECTOR 0 _Startup 产生了冲突!