試分別說(shuō)明下列語(yǔ)句的功能: ①STM #SPCR10,SPSA0 STM #0001H,BSP0 ②STM #SPCR20,SPSA0 STM #0081H,BSP0 ③STM #SPCR20,SPSA0 ORM #01000001B,BSP0