基于DSP的fangbo.asm 利用定时器Timer0在XF脚产生周期1s的的方波 此程序采用100Mhz的时钟频率，产生的方波-DSP-based fangbo.asm use timer Timer0 XF feet produced in a cycle of the square's procedure using 100 Mhz clock frequency of the square wave