**功能描述： ECAN自测试程序，CAN模块工作在自测试模式。MBX0发送到MBX16***
**MBX1发送到MBX17。该程序不停地高速背靠背传输数据，检查接数据的正确性**

/*eCAN 控制寄存器需要32位访问。如果想向一个单独位进行写操作，编译器可能会使其进入16位访问。这儿引用了一种解决方法，就是用影子寄存器迫使进行32位访问。 把整个寄存器读入一个影子寄存器。 这个访问将是32位的。用32位写操作改变需要改的位，然后把该值拷贝回eCAN寄存器*/(* * function descr iption: ECAN self test program, CAN module work in self test mode. MBX0 send to MBX16***

**MBX1 send to MBX17. The program constantly transmits data back to back and checks the correctness of the data. * * * *

The /*eCAN control register requires 32 bit access. If you want to write to a single bit, the compiler might make it into 16 bit access. One solution here is to force a 32 bit access with the shadow register. Reads the entire register into a shadow register. This visit will be in 32 place. With a 32 bit write operation needs to change, then the value is copied back to the eCAN register.)