单片机原理及应用模拟试题.doc

.一、选择题1.单片机复位后,SP PC I/O口的内容为 A.SP = 60H PC = 00H P0 = P1 = P2 = P3 = FFHB.SP = 00H PC = 0000H P0 = P1 = P2 = P3 = 00HC.SP = 07H PC = 0000H P0 = P1 = P2 = P3 = FFHD.SP = 00H PC = 00H P0 = P1 = P2 = P3 = 00H答案：1.C 2.8051有四个工作寄存器区,由PSW状态字中的RS1和RS0两位的状态来决定,单片机复位后,若执行 SETB RS0 指令,此时只能使用 区的工作寄存器。A.区 B.区 C.区 D.区答案：2.B3、ATMEL的89C51驱动能力最强的并行端口为 。A.P0B.P1C.P2D.P3答