P0口能驱动4个LSTTL门电路,而P1、P2、P3能驱动8个。
P0口能驱动4个LSTTL门电路,而P1、P2、P3能驱动8个。
相关考题:
单片机复位时作如下初始化操作( ) A.PC=0000, SP=00,P0=00,P1=00,P2=00,P3=00B.PC=0030, SP=07,P0=00,P1=00,P2=00,P3=00C.PC=0000, SP=07,P0=FF,P1=FF,P2=FF,P3=FF
单片机复位后,SP、PC、I/O口的内容为( ) A.SP = 07H 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
Given: class ClassA {} class ClassB extends ClassA {} class ClassC extends ClassA {} and: ClassA p0 = new ClassA(); ClassB p1 = new ClassB(); ClassC p2 = new ClassC(); ClassA p3 = new ClassB(); ClassA p4 = new ClassC(); Which three are valid?()A、p0 = p1;B、p1 = p2;C、p2 = p4;D、p2 = (ClassC)p1;E、p1 = (ClassB)p3;F、p2 = (ClassC)p4;
class ClassA {} class ClassB extends ClassA {} class ClassC extends ClassA {} and: ClassA p0 = new ClassA(); ClassB p1 = new ClassB(); ClassC p2 = new ClassC(); ClassA p3 = new ClassB(); ClassA p4 = new ClassC(); Which three are valid?()A、 p0 = p1;B、 p1 =p2;C、 p2 = p4;D、 p2 = (ClassC)p1;E、 p1 = (ClassB)p3;F、 p2 = (ClassC)p4;
问答题80C51单片机的P0~P3口在通用I/O口时操作要注意哪些?P0~P3口不做通用I/O口时是什么功能?P0~P3驱动能力如何?