ds18B20FPGAVHDL语言.docx
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ds18B20FPGAVHDL语言
----------VHDL语言编写DS18B20温度传感器程序
libraryIEEE;
useIEEE.STD_LOGIC_1164.ALL;
useIEEE.STD_LOGIC_ARITH.ALL;
useIEEE.STD_LOGIC_UNSIGNED.ALL;
entityds18B20is
port（clk:
instd_logic;---50MHz
dq:
inoutstd_logic;
rst:
instd_logic;
LED:
outstd_logic;
LED2:
outstd_logic;
LED3:
outstd_logic;
dataout1,dataout2,dataout3:
outstd_logic_vector（6downto0））;--数
endds18B20;
architectureBehavioralofds18B20is
TYPESTATE_TYPEis（RESET,CMD_CC,WRITE_BYTE,WRITE_LOW,WRITE_HIGH,READ_BIT,
CMD_44,CMD_BE,WAIT800MS,GET_TMP,WAIT4MS）;
signalSTATE:
STATE_TYPE:
=RESET;
signalclk_temp:
std_logic:
='0';
signalclk1m:
std_logic;--分频后得到的1M时钟
signalcp:
std_logic;--1ms时钟
signalw:
integerrange0to2:
=0;---xianshishunxu
signalwrite_temp:
std_logic_vector（7downto0）:
="00000000";
signalTMP:
std_logic_vector（11downto0）;
signaltmp_bit:
std_logic;
signalWRITE_BYTE_CNT:
integerrange0to8:
=0;
signalWRITE_LOW_CNT:
integerrange0to2:
=0;
signalWRITE_HIGH_CNT:
integerrange0to2:
=0;
signalREAD_BIT_CNT:
integerrange0to3:
=0;
signalGET_TMP_CNT:
integerrange0to13:
=0;
signalcnt:
integerrange0to100_001:
=0;
----------******************************
signalcnt2:
integerrange0to4000001:
=0;
signaltemp:
std_logic;
signaldata_temp0:
std_logic_vector（15downto0）;
signaldecimal0:
std_logic_vector（15downto0）;
signaldecimal1:
std_logic_vector（15downto0）;
signaldecimal2:
std_logic_vector（15downto0）;
signaldecimal3:
std_logic_vector（15downto0）;
signaldata_temp1:
std_logic_vector（7downto0）;
signalinteger0:
std_logic_vector（7downto0）;
signalinteger1:
std_logic_vector（7downto0）;
signalinteger2:
std_logic_vector（7downto0）;
signalinteger3:
std_logic_vector（7downto0）;
signalinteger4:
std_logic_vector（7downto0）;
signalinteger5:
std_logic_vector（7downto0）;
signalinteger6:
std_logic_vector（7downto0）;
signalsign:
std_logic_vector（7downto0）;
signalcount:
integerrange0to51:
=0;
signalWRITE_BYTE_FLAG:
integerrange0to4:
=0;
functiondis（num:
std_logic_vector）returnstd_logic_vectoris
begin
casenumis
when"0000"=>return"1000000";--0
when"0001"=>return"1111001";--1
when"0010"=>return"0100100";--2
when"0011"=>return"0110000";--3
when"0100"=>return"0011001";--4
when"0101"=>return"0010010";--5
when"0110"=>return"0000010";--6
when"0111"=>return"1111000";--7
when"1000"=>return"0000000";--8
when"1001"=>return"0010000";--9
when"1010"=>return"0001000";--A
when"1011"=>return"0000011";--b
when"1100"=>return"1000110";--C
when"1101"=>return"0100001";--d
when"1110"=>return"0000110";--E
when"1111"=>return"0001110";--F
whenothers=>return"1111111";--mie
endcase;
enddis;
begin
----------@@@@@@@@@@@@@----------------
ClkDivider:
process（clk,clk_temp）
begin
ifrising_edge（clk）then
if（count=24）then
count<=0;
clk_temp<=notclk_temp;
else
count<=count+1;
endif;
endif;
clk1m<=clk_temp;
endProcess;
----------@@@@@@@@@@@@@----------------
process（clk1m）
variablen:
integerrange0to12000:
=0;
begin-----cp1ms
ifrising_edge（clk1m）then
n:
=n+1;
if（n>12000）thenn:
=0;cp<=notcp;endif;
endif;
endProcess;
STATE_TRANSITION:
process（STATE,clk1m）
begin
ifrising_edge（clk1m）then
if（rst='0'）then
STATE<=RESET;
else
caseSTATEis
whenRESET=>
--**********
LED2<='0';--*************-
LED3<='0';
--*********
if（cnt>=0andcnt<500）then--500μs的复位低电平
dq<='0';--dq作为输出
cnt<=cnt+1;
STATE<=RESET;
elsif（cnt>=500andcnt<510）then--高阻态再输入下一级电路的话，对下级电路无任何影响，和没接一样,高阻态可以应用在inout端口里面，这样在inout没有输出的时候就弄个高阻态，这样就其电平就可以由外面的输入信号决定了
dq<='Z';
cnt<=cnt+1;
STATE<=RESET;--拉高dq
elsif（cnt>=510andcnt<750）then--240μs
temp<=dq;--dq作为输入
if（cnt=580）then
temp<=dq;
if（temp='1'）then
LED<='0';
elseLED<='1';
endif;
endif;
cnt<=cnt+1;
STATE<=RESET;
elsif（cnt>=750）then
cnt<=0;--计数器清零
STATE<=CMD_CC;--复位过程伴随着跳跃rom指令“CC”
endif;
whenCMD_CC=>--跳跃rom指令“CC”
LED2<='1';
LED3<='0';
write_temp<="11001100";
STATE<=WRITE_BYTE;
whenWRITE_BYTE=>
caseWRITE_BYTE_CNTis
when0to7=>
if（write_temp（WRITE_BYTE_CNT）='0'）then
STATE<=WRITE_LOW;
LED3<='1';
else
STATE<=WRITE_HIGH;
endif;
WRITE_BYTE_CNT<=WRITE_BYTE_CNT+1;
when8=>
if（WRITE_BYTE_FLAG=0）then--第一次写0XCC完毕
STATE<=CMD_44;
WRITE_BYTE_FLAG<=1;
elsif（WRITE_BYTE_FLAG=1）then--写0X44完毕（写温度转换指令后没有读数据？
）
STATE<=RESET;
WRITE_BYTE_FLAG<=2;
elsif（WRITE_BYTE_FLAG=2）then--第二次写0XCC完毕
STATE<=CMD_BE;
WRITE_BYTE_FLAG<=3;
elsif（WRITE_BYTE_FLAG=3）then--写0XBE完毕
STATE<=GET_TMP;
WRITE_BYTE_FLAG<=0;
endif;
WRITE_BYTE_CNT<=0;
whenothers=>STATE<=RESET;
endcase;
whenWRITE_LOW=>
LED3<='1';
caseWRITE_LOW_CNTis
when0=>
dq<='0';
if（cnt=70）then
cnt<=0;
WRITE_LOW_CNT<=1;
else
cnt<=cnt+1;
endif;
when1=>
dq<='Z';
if（cnt=5）then
cnt<=0;
WRITE_LOW_CNT<=2;
else
cnt<=cnt+1;
endif;
when2=>
STATE<=WRITE_BYTE;
WRITE_LOW_CNT<=0;
whenothers=>WRITE_LOW_CNT<=0;
endcase;
whenWRITE_HIGH=>
caseWRITE_HIGH_CNTis
when0=>
dq<='0';
if（cnt=8）then
cnt<=0;
WRITE_HIGH_CNT<=1;
else
cnt<=cnt+1;
endif;
when1=>
dq<='Z';
if（cnt=72）then
cnt<=0;
WRITE_HIGH_CNT<=2;
else
cnt<=cnt+1;
endif;
when2=>
STATE<=WRITE_BYTE;
WRITE_HIGH_CNT<=0;
whenothers=>WRITE_HIGH_CNT<=0;
endcase;
whenCMD_44=>
write_temp<="01000100";
STATE<=WRITE_BYTE;
whenCMD_BE=>
write_temp<="10111110";
STATE<=WRITE_BYTE;
----------------------------------
whenREAD_BIT=>
caseREAD_BIT_CNTis
when0=>
dq<='0';--4μs的低电平
if（cnt=4）then
READ_BIT_CNT<=1;
cnt<=0;
else
cnt<=cnt+1;
endif;
when1=>
dq<='Z';--4μs的高电平
if（cnt=4）then
READ_BIT_CNT<=2;
cnt<=0;
else
cnt<=cnt+1;
endif;
when2=>
dq<='Z';
TMP_BIT<=dq;--12μs读出数据,就是最后一次赋值的结果。
if（cnt=4）then
READ_BIT_CNT<=3;
cnt<=0;
else
cnt<=cnt+1;
endif;
when3=>
---------------------
dq<='Z';--控制器拉高总线
---------------------
if（cnt=50）then--读出数据后，等待50us
cnt<=0;
READ_BIT_CNT<=0;
STATE<=GET_TMP;
else
cnt<=cnt+1;
endif;
whenothers=>READ_BIT_CNT<=0;
endcase;
-------#################--------------
whenGET_TMP=>
caseGET_TMP_CNTis
when0=>
STATE<=READ_BIT;
GET_TMP_CNT<=GET_TMP_CNT+1;
when1to12=>
STATE<=READ_BIT;
TMP（GET_TMP_CNT-1）<=TMP_BIT;--将读出的每一位数据按顺序存进TMP（0to11）里面
GET_TMP_CNT<=GET_TMP_CNT+1;--存的是读出的0到11位，第十二位没有存
when13=>
GET_TMP_CNT<=0;
STATE<=WAIT4MS;
endcase;
whenWAIT4MS=>
if（cnt>=4000）then
--STATE<=WAIT4MS;
STATE<=RESET;
cnt<=0;
else
cnt<=cnt+1;
STATE<=WAIT4MS;
endif;
whenothers=>STATE<=RESET;
LED<='0';
LED2<='0';
LED3<='0';
endcase;
endif;
endif;
endprocess;
-----------------------------------------------
DISPLAY:
process（cp）--------数码管动态显示温度值
variabletemp:
std_logic_vector（3downto0）;
begin
casewis
when0=>temp:
=TMP（3downto0）;dataout1<=dis（temp）;w<=1;
when1=>temp:
=TMP（7downto4）;dataout2<=dis（temp）;w<=2;
when2=>temp:
=TMP（11downto8）;dataout3<=dis（temp）;w<=0;
endcase;
endprocess;
endBehavioral;
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