U221222324252627P2.728101112/INT1131415/WR16/RD1729ALE30P2.0/A8P2.1/A9P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15P3.0/RXDP3.1/TXDP3.2/INTOP3.3/INT1P3.4/TOP3.5/T1P3.6/WRP3.7/RDPSENALE/PROGP0.0/AD0P0.1/AD1P0.2/AD2P0.3/AD3P0.4/AD4P0.5/AD5P0.6/AD6P0.7/AD7P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7XTAL1XTAL2RSTEA/VPPAT89C513938373635343332123456781918931347813141718ALE111U3D0D1D2D3D4D5D6D7GOC74LS373/WR23P2.52/RD3NOR2NOR2U61U51Q0Q1Q2Q3Q4Q5Q6Q72569121516191714158181920212524236229U1D0D1D2D3D4D5D6D7A0A1A2STARTALEOEEOCADC080972U4NOT1/INT1IN0IN1IN2IN3IN4IN5REF+REF-CLK262728123+5V1216010分频器ALE0
七、综合（键盘 显示器扩展任务9-10）
样题：如图8051通过74LS377扩展LED数码管，（共8分）（未使用的地址线默认为“1”） 1、 U1地址是多少？（2分）
U1的地址是：BFFF
2、 要使U2的地址是7FFFH，U2的片选如何连接？（2分） 7=0111; 接P2^7
3、 写一段程序在LED1和LED2上分别显示“0”和“1”。（4分）（用C51语言实现）
#include
#define SHUMA1 XBYTE[0xbfff] #define SHUMA2 XBYTE[0x7fff]
void delay(void) { unsigned char i=1; for(;i>0;i--); }
void main(void) { while(1) { SHUMA1 = 0x3f; delay(); SHUMA2 = 0x06; delay();
6
}
P20P21P22P23P24P25P26P27}
U3U52122232425262728P2.0/A8P2.1/A9P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15P3.0/RXDP3.1/TXDP3.2/INTOP3.3/INT1P3.4/TOP3.5/T1P3.6/WRP3.7/RDPSENALE/PROGP0.0/AD0P0.1/AD1P0.2/AD2P0.3/AD3P0.4/AD4P0.5/AD5P0.6/AD6P0.7/AD7P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7XTAL1XTAL2RSTEA/VPPAT89C513938373635343332123456781918931P00P01P02P03P04P05P06P07/WRP26P00P01P02P03P04P05P06P07347813141718111U1D1D2D3D4D5D6D7D8CLKG74LS377P00P01P02P03P04P05P06P07347813141718111U2D1D2D3D4D5D6D7D8CLKG74LS377Q1Q2Q3Q4Q5Q6Q7Q8256912151619U4abcdefgdpQ1Q2Q3Q4Q5Q6Q7Q8256912151619abcdefgdpLED1VCCcom101112131415/WR16/RD172930LED2VCCcom
七、如图，8051单片机通过74LS244扩展按键SW0~SW7共8个（图中只画出SW0和SW7，其它按键SW1、SW2、SW3、SW、SW、SW6与SW0、SW7相似），（共8分）（提示：未使用的地址线默认为“1”） 1. 说明U2端口地址；（2分）
U2的端口地址：0xBFFF
2. U2是输入接口还是输出接口？说明原因；（2分）
U2接口：是输入接口
原因：U2的一个控制端接的是单片机的RD/,则说明U2是输入接口
U2的输入端口接的是扩展按键SW0~SW7，输出接口接到单片机的P0口，则 说明U2是输入接口
3. 写一段程序读取按键值送到内部数据存储器地址为30H的存储单元。（4分）（用C51
语言实现）
#include
#define SHUMA1 XBYTE[0xbfff]
unsigned char data *In_Ram = 0x30;
void delay(void)
7
{ unsigned char i=10; for(;i>0;i--); }
void main(void) { unsigned char temp; while(1) { temp = SHUMA1; *In_Ram = temp; delay(); } }
VCCU52122232425262728P2.0/A8P2.1/A9P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15P3.0/RXDP3.1/TXDP3.2/INTOP3.3/INT1P3.4/TOP3.5/T1P3.6/WRP3.7/RDPSENALE/PROGP0.0/AD0P0.1/AD1P0.2/AD2P0.3/AD3P0.4/AD4P0.5/AD5P0.6/AD6P0.7/AD7P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7XTAL1XTAL2RSTEA/VPPAT89C5139383736353433321234567819189312P20P21P22P23P24P25P26P27P00P01P02P03P04P05P06P07181614129753U21Y11Y21Y31Y42Y12Y22Y32Y41A11A21A31A42A12A22A32A41G2G74LS244R02468111315171191k22R71kSW0SW71101112131415/WR16/RD172930101U6OR2/RDP263
8