|
24c02的简单操作 scl_2402 bit p3.5 sda_2402 bit p3.7 sp_begain equ 60h org 0 mov sp,#sp_begain acall delay acall delay acall delay mov 30h,#0 mov 31h,#1 mov 32h,#2 mov 33h,#3 mov 34h,#4 mov 35h,#5 mov 36h,#6 mov 37h,#7 write: clr a ;address mov r0,#30h ;point mov r1,#8 ;sum acall wrs_2402 cjne r1,#0ffh,next0 sjmp err_2402 next0: acall delay read: clr a ;address mov r0,#38h ;point mov r1,#8 ;sum acall rds_2402 cjne r1,#0ffh,next1 sjmp err_2402 next1: acall delay write0: mov a,#8 ;address mov r0,#38h ;point mov r1,#8 ;sum acall wrs_2402 cjne r1,#0ffh,next2 sjmp err_2402 next2: acall delay sjmp $ err_2402:sjmp $ delay: mov r6,#20 ;24M--5ms----24c02的写入时间间隔 delay_0:djnz r7,$ djnz r6,delay_0 ret ;--------------------------------------------- wI2c equ 0a0h ;器件地址及写操作 rI2c equ 0a1h ;器件地址及读操作 sta_2402: ;启始 setb sda_2402 setb scl_2402 sjmp $+2 ;24M至少间隔周期 sjmp $+2 clr sda_2402 sjmp $+2 sjmp $+2 clr scl_2402 sjmp $+2 sjmp $+2 ret stp_2402: ;结束 clr sda_2402 setb scl_2402 sjmp $+2 sjmp $+2 setb sda_2402 sjmp $+2 sjmp $+2 ret wr_2402: ;写单个字节 mov b,#8 wr_2402_0: rlc a jc wr_2402_1 clr sda_2402 sjmp wr_2402_2 wr_2402_1: setb sda_2402 wr_2402_2: setb scl_2402 sjmp $+2 sjmp $+2 clr scl_2402 sjmp $+2 sjmp $+2 djnz b,wr_2402_0 nmack_2402: setb sda_2402 nmack_2402_0:setb scl_2402 sjmp $+2 sjmp $+2 mov c,sda_2402 clr scl_2402 sjmp $+2 sjmp $+2 ret mack_2402: clr sda_2402 sjmp nmack_2402_0 rd_2402: ;读单个字节 mov b,#8 setb sda_2402 rd_2402_0: setb scl_2402 sjmp $+2 sjmp $+2 mov c,sda_2402 rlc a clr scl_2402 sjmp $+2 sjmp $+2 djnz b,rd_2402_0 ret ;--------------------------------------- ;24c02的页写为8个字节。 ;wrs_2402 写操作(;a--2402指针,r0--变量基址,r1--变量个数少于等于8) ;rds_2402 读操作(;a--2402指针,r0--变量基址,r1--变量个数少于等于8) ;使用a,b,psw,r0,r1 五个变量 wa_2402: push aCC acall sta_2402 mov a,#wI2c acall wr_2402 pop acc jc err_2402 acall wr_2402 ret err_2402: mov r1,#0ffh dec sp dec sp ret ;2402硬件错误返回 wrs_2402: ;写多字节 acall wa_2402 wrs_2402_0:mov a,@r0 acall wr_2402 inc r0 djnz 01h,wrs_2402_0 acall stp_2402 ret rds_2402: ;读多字节 acall wa_2402 acall sta_2402 mov a,#rI2c acall wr_2402 rds_2402_0:acall rd_2402 mov @r0,a djnz 01h,rds_2402_1 acall nmack_2402 acall stp_2402 ret rds_2402_1:acall mack_2402 inc r0 sjmp rds_2402_0 |
|
|
