;################################################ ; Designed by CaoHai 10-23-2002 in SDUWHB ; ; Updated by CaoHai 12-12-2002 in SDUWHB ; ; Upgraded by CaoHai 22-12-2002 in SDUWHB ; ; Upgraded by CaoHai 05-05-2003 in SDUWHB ; ;################################################ ;>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ;标号定义 data_len equ 0ch ;温度数据长度 data_buf equ 50h ;温度数据缓冲区 ;虚拟引脚定义(For SPI BUS) vcs equ p1.0 ;片选线 vio equ p1.1 ;数据线 vsc equ p1.2 ;时钟线 ;>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ;================================================ ;模块GetData ;参数：无参数 ;功能：用spi总线从LM74温度传感器读取温度数据 ;返回：无 GetData: clr ea clr vcs setb vio mov r1,#08h clr vsc ;读符号位 nop nop nop setb vsc nop nop nop mov f0,vio read_bite: ;读数据 clr vsc nop nop nop setb vsc nop nop nop mov c,vio rlc a djnz r1,read_bite setb vcs ;转换数据 mov data_buf+1,#2bh jnb f0,fill_data dec a cpl a mov data_buf+1,#2bh fill_data: mov data_buf+2,#30h mov data_buf+3,#30h mov data_buf+4,#30h mov data_buf+5,#0a1h mov data_buf+6,#0e6h mov data_buf+7,#3bh mov data_buf+8,#20h mov data_buf+9,#30h mov data_buf+10,#30h mov data_buf+11,#31h mov data_buf+12,#7ch mov r0,#data_buf+4 divide_data: mov b,#0ah div ab mov r1,a mov a,b add a,#30h mov @r0,a dec r0 mov a,r1 jnz divide_data mov data_buf,#data_len setb ea ret