74ls160芯片同步十进制计数器（直接清零kuc.docx

74LSS1600 芯片片同步十十进制计计数器（直直接清零零） ··用于快快速计数数的内部部超前进进位 ··用于nn 位级级联的进进位输出出 ·同同步可编编程序  ·有置置数控制制线 ··二极管管箝位输输入 ··直接清清零 ··同步计计数 本本电路是是由4 个主从从触发器器和用作作除2计计数器及及计数周周期长度度为除55的3位位2进制制计数器器所用的的附加选选通所组组成。有有选通的的零复位位和置99输入。为为了利用用本计数数器的最最大计数数长度（十十进制），可可将B输输入同QQA 输输出连接接，输入入计数脉脉冲可加加到输入入A上，此此时输出出就如相相应的功功能表上上所要求求的那样样。LSS90可可以获得得对称的的十分频频计数，办办法是将将QD 输出接接到A输输入端，并并把输入入计数脉脉冲加到到B输入入端，在在QA输输出端处处产生对对称的十十分频方方波。741660引脚脚图交流波形形图：  图11 时钟钟到输出出延迟计计数                 图图2 主主复位输输出延迟迟，主复复位                   时钟频频率，脉脉冲宽度度                      脉脉冲宽度度，和主主复位恢恢复时间间状态图VHDLL十进制制计数器器librraryy ieeee;usee ieeee.stdd_loogicc_11164.alll;usse iieeee.sttd_llogiic_aaritth.aall;usee ieeee.stdd_loogicc_unnsiggnedd.alll;eentiity couunt110 iispoort (cllk:iin sstd_loggic;             f:buffferr inntegger rannge 0 tto 115;         couut:oout stdd_loogicc); endd;arrchiiteccturre aaa oof ccounnt100 issbegginpproccesss(cllk)bbegiin iif ffalllingg_eddge(clkk) tthennif f=99 thhenff<=00;coout<<='11'eelseef<=f+11;ennd iif;eelseenulll;eend if;endd prroceess;endd;十进制计计数器VVHDLLlibrraryy ieeee;use ieeee.sstd_loggic_11664.aall;use ieeee.sstd_loggic_ariith.alll;use ieeee.sstd_loggic_unssignned.alll;-*实体* enttityy shhijiinzhhi iis poort(cllk: in sttd_llogiic; rreseet: in sttd_llogiic; ss : outt sttd_llogiic_vvecttor(5 ddownnto 0); outt1: outt sttd_llogiic_vvecttor(7 ddownnto 0);end shiijinnzhii;-*结构体体*archhiteectuure onee off shhijiinzhhi iissignnal clkk_5000 : sttd_llogiic;-扫描描时钟signnal clkk_1 : sttd_llogiic;-1ss时钟begiin-*5500HHz分频频程序*proccesss(cllk)varriabble cntt1 : inntegger rannge 0 tto 2200;varriabble cntt2 : inntegger rannge 0 tto 2250;begiin if clkk'evventt annd cclk='1'' thhen if cntt1=2200 theen ccnt11:=00;iif ccnt22=2550 tthenncntt2:=0;clkk_5000<=nott cllk_5500;eelseecntt2:=cntt2+11;eend if;ellseccnt11:=ccnt11+1; endd iff; ennd iif;end proocesss;-*1Hzz分频程程序和扫扫描信号号产生*proccesss(cllk_5500)varriabble cntt3 : inntegger rannge 0 tto 2250;begginif clkk_5000'eevennt aand clkk_5000=''1' theeniff cnnt3=2500 thhenccnt33:=00;cclk_1<=nott cllk_11;ellseccnt33:=ccnt33+1;ennd iif;endd iff;end proocesss;-* prroceess(clkk_1,resset) varriabble couunt11:inntegger rannge 0 tto 99; bbegiin if resset='0'' thhen couunt11:=00; eelsiifclkk_1''eveent andd cllk_11='11' tthenn iif ccounnt1=9 tthenn coountt1:=0; elsse ccounnt1:=coountt1+11; eend if;ennd iif; iff cllk_5500='1'' thhen caase couunt11 issWHEEN 00 =>>s<="11111110"outt1<="10011111111"WHEEN 11 =>>s<="11111110"outt1<="10000001100" WHEEN 22 =>>s<="11111110"outt1<="11101110111" WHEEN 33 =>>s<="11111110"outt1<="11100111111" WHEEN 44 =>>s<="11111110"outt1<="11110001100" WHEEN 55 =>>s<="11111110"outt1<="11110111011" WHEEN 66 =>>s<="11111110"outt1<="11111111011" WHEEN 77 =>>s<="11111110"outt1<="10000001111" WHEEN 88 =>>s<="11111110"outt1<="11111111111" WHEEN 99 =>>s<="11111110"outt1<="11110111111" wheen ootheers=>ouut1<<="00000000000" ennd ccasee; ennd iif;end proocesss;end onee;