📄 ds18b20读写程序.v
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else
begin
counter_rd<=counter_rd+1'b1;
rd_state<=RD_BIT7;
if(counter_rd<300)
link_data<=1;
else
begin
link_data<=0;
if(counter_rd==500)
begin
recv_reg<=recv_reg>>1;
recv_reg[12]<=data;
end
end
end
end
RD_BIT8:
begin
if(counter_rd==3500)
begin
link_data<=0;
rd_state<=RD_BIT9;
counter_rd<=0;
end
else
begin
counter_rd<=counter_rd+1'b1;
rd_state<=RD_BIT8;
if(counter_rd<300)
link_data<=1;
else
begin
link_data<=0;
if(counter_rd==500)
begin
recv_reg<=recv_reg>>1;
recv_reg[12]<=data;
end
end
end
end
RD_BIT9:
begin
if(counter_rd==3500)
begin
link_data<=0;
rd_state<=RD_BIT10;
counter_rd<=0;
end
else
begin
counter_rd<=counter_rd+1'b1;
rd_state<=RD_BIT9;
if(counter_rd<300)
link_data<=1;
else
begin
link_data<=0;
if(counter_rd==500)
begin
recv_reg<=recv_reg>>1;
recv_reg[12]<=data;
end
end
end
end
RD_BIT10:
begin
if(counter_rd==3500)
begin
link_data<=0;
rd_state<=RD_BIT11;
counter_rd<=0;
end
else
begin
counter_rd<=counter_rd+1'b1;
rd_state<=RD_BIT10;
if(counter_rd<300)
link_data<=1;
else
begin
link_data<=0;
if(counter_rd==500)
begin
recv_reg<=recv_reg>>1;
recv_reg[12]<=data;
end
end
end
end
RD_BIT11:
begin
if(counter_rd==3500)
begin
counter_rd<=0;
link_data<=0;
rd_state<=RD_BIT12;
end
else
begin
counter_rd<=counter_rd+1'b1;
rd_state<=RD_BIT11;
if(counter_rd<300)
link_data<=1;
else
begin
link_data<=0;
if(counter_rd==500)
begin
recv_reg<=recv_reg>>1;
recv_reg[12]<=data;
end
end
end
end
RD_BIT12://to judge the sign of the temperature
begin
if(counter_rd==3500)
begin
counter_rd<=0;
link_data<=0;
rd_state<=IDLE;
ff<=1;
end
else
begin
counter_rd<=counter_rd+1'b1;
rd_state<=RD_BIT12;
if(counter_rd<300)
link_data<=1;
else
begin
link_data<=0;
if(counter_rd==500)
begin
recv_reg<=recv_reg>>1;
recv_reg[12]<=data;
end
else if(501<=counter_rd<=505)
begin
if(recv_reg[12]==1)
begin
recv_reg[11:0]<=~recv_reg[11:0]+1'b1;
temp_sign<=1;
end
else
begin
temp_sign<=0;
recv_reg[11:0]<=recv_reg[11:0];
end
end
end
end
end
default:
begin
ff<=0;
rd_state<=IDLE;
link_data<=0;
counter_rd<=0;
end
endcase
end
endtask
//-------------------------------reset task-----------------------------------------
//pull the bus to '0' for 490 us then release the bus for 490 us(whole cycle:490us*2)
//--------------------------------------------------------------------------------
task reset;
begin
counter_rst<=counter_rst+1'b1;
if(counter_rst<25000)
begin
link_data<=1;
end
else
begin
link_data<=0;
if(counter_rst==50000)
begin
ff<=1;
counter_rst<=0;
end
end
end
endtask
//------------------------------DELAY task----------------------------------------
//release the one wire bus for 750 ms
//--------------------------------------------------------------------------------
task delay;
begin
if(counter_test==37500000)
begin
ff<=1;
counter_test<=0;
end
else
counter_test<=counter_test+1'b1;
end
endtask
//-----------------------------data transfer---------------------------------------
//recv data transfer to its BCD code
//---------------------------------------------------------------------------------
always @(posedge clk)
begin
if(!rst) //initialize the data
begin
temp0<=4'b1111;
temp1<=8'b11111111;
ini_value<=4'b1111;
decode_value<=8'b11111111;
scan_bit<=4'b0000;
end
else
// stable the display data
case(main_state)
READ_BIT:recv_reg_copy<=recv_reg_copy;
default:recv_reg_copy<=recv_reg;
endcase
// convert the low 4 bits of temperature to BCD code
case(recv_reg_copy[3:0])
4'b0000 : temp0<=4'b0000;//0
4'b0001 : temp0<=4'b0001;//1
4'b0010 : temp0<=4'b0001;//1
4'b0011 : temp0<=4'b0010;//2
4'b0100 : temp0<=4'b0011;//3
4'b0101 : temp0<=4'b0011;//3
4'b0110 : temp0<=4'b0100;//4
4'b0111 : temp0<=4'b0100;//4
4'b1000 : temp0<=4'b0101;//5
4'b1001 : temp0<=4'b0110;//6
4'b1010 : temp0<=4'b0110;//6
4'b1011 : temp0<=4'b0111;//7
4'b1100 : temp0<=4'b1000;//8
4'b1101 : temp0<=4'b1000;//8
4'b1110 : temp0<=4'b1001;//9
4'b1111 : temp0<=4'b1001;//9
default : temp0<=4'b1111;
endcase
//convert the high 8 bits of temperature to BCD num
case(recv_reg_copy[11:4])
8'b00000000 : temp1<=8'b00000000;//0
8'b00000001 : temp1<=8'b00000001;//1
8'b00000010 : temp1<=8'b00000010;//2
8'b00000011 : temp1<=8'b00000011;//3
8'b00000100 : temp1<=8'b00000100;//4
8'b00000101 : temp1<=8'b00000101;//5
8'b00000110 : temp1<=8'b00000110;//6
8'b00000111 : temp1<=8'b00000111;//7
8'b00001000 : temp1<=8'b00001000;//8
8'b00001001 : temp1<=8'b00001001;//9
8'b00001010 : temp1<=8'b00001010;//10
8'b00001011 : temp1<=8'b00010001;//11
8'b00001100 : temp1<=8'b00010010;//12
8'b00001101 : temp1<=8'b00010011;//13
8'b00001110 : temp1<=8'b00010100;//14
8'b00001111 : temp1<=8'b00010101;//15
8'b00010000 : temp1<=8'b00010110;//16
8'b00010001 : temp1<=8'b00010111;//17
8'b00010010 : temp1<=8'b00011000;//18
8'b00010011 : temp1<=8'b00011001;//19
8'b00010100 : temp1<=8'b00100000;//20
8'b00010101 : temp1<=8'b00100001;//21
8'b00010110 : temp1<=8'b00100010;//22
8'b00010111 : temp1<=8'b00100011;//23
8'b00011000 : temp1<=8'b00100100;//24
8'b00011001 : temp1<=8'b00100101;//25
8'b00011010 : temp1<=8'b00100110;//26
8'b00011011 : temp1<=8'b00100111;//27
8'b00011100 : temp1<=8'b00101000;//28
8'b00011101 : temp1<=8'b00101001;//29
8'b00011110 : temp1<=8'b00110000;//30
8'b00011111 : temp1<=8'b00110001;//31
8'b00100000 : temp1<=8'b00110010;//32
8'b00100001 : temp1<=8'b00110011;//33
8'b00100010 : temp1<=8'b00110100;//34
8'b00100011 : temp1<=8'b00110101;//35
8'b00100100 : temp1<=8'b00110110;//36
8'b00100101 : temp1<=8'b00110111;//37
8'b00100110 : temp1<=8'b00111000;//38
8'b00100111 : temp1<=8'b00111001;//39
8'b00101000 : temp1<=8'b01000000;//40
8'b00101001 : temp1<=8'b01000001;//41
8'b00101010 : temp1<=8'b01000010;//42
8'b00101011 : temp1<=8'b01000011;//43
8'b00101100 : temp1<=8'b01000100;//44
8'b00101101 : temp1<=8'b01000101;//45
8'b00101110 : temp1<=8'b01000110;//46
8'b00101111 : temp1<=8'b01000111;//47
8'b00110000 : temp1<=8'b01001000;//48
8'b00110001 : temp1<=8'b01001001;//49
8'b00110010 : temp1<=8'b01010000;//50
8'b00110011 : temp1<=8'b01010001;//51
8'b00110100 : temp1<=8'b01010010;//52
8'b00110101 : temp1<=8'b01010011;//53
8'b00110110 : temp1<=8'b01010100;//54
8'b00110111 : temp1<=8'b01010101;//55
default : temp1<=8'b11111111;
endcase
//led scan and scan_bit,data_bits select
case(scan_counter[16:15])
2'b00:
begin
scan_bit<=4'b1000;
decode_value[0]<=1'b1;
if(temp_sign==1)
ini_value<=4'b1010;//display"-℃"
else
ini_value<=4'b1111;//display"℃"
end
2'b01:
begin
ini_value<=temp1[7:4];
scan_bit<=4'b0100;
decode_value[0]<=1'b1;
end
2'b10:
begin
ini_value<=temp1[3:0];
scan_bit<=4'b0010;
decode_value[0]<=1'b0;
end
2'b11:
begin
ini_value<=temp0[3:0];
scan_bit<=4'b0001;
decode_value[0]<=1'b1;
end
default : scan_bit<=4'b0000;
endcase
//led 7 segment decode
case(ini_value)
4'b0000 :decode_value[7:1]<=7'b0000001;//0
4'b0001 :decode_value[7:1]<=7'b1001111;//1
4'b0010 :decode_value[7:1]<=7'b0010010;//2
4'b0011 :decode_value[7:1]<=7'b0000110;//3
4'b0100 :decode_value[7:1]<=7'b1001100;//4
4'b0101 :decode_value[7:1]<=7'b0100100;//5
4'b0110 :decode_value[7:1]<=7'b0100000;//6
4'b0111 :decode_value[7:1]<=7'b0001111;//7
4'b1000 :decode_value[7:1]<=7'b0000000;//8
4'b1001 :decode_value[7:1]<=7'b0000100;//9
4'b1010 :decode_value[7:1]<=7'b1111110;//-
default :decode_value[7:1]<=7'b1111111;//no display
endcase
end
//--------------------------------scan clock ----------------------------------------
// 0.65536ms scan cycle
//---------------------------------------------------------------------------------
always @(posedge clk )
begin
if(!rst)
scan_counter<=0;
else
begin
if(scan_counter==17'b11111111111111111)
scan_counter<=17'b00000000000000000;
else
scan_counter<=scan_counter+1'b1;
end
end
endmodule⌨️ 快捷键说明
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