本帖最后由 feihufuture 于 2021-4-29 09:21 编辑
xilinx的fpga自带DNA可以用来加密;可是换了国产FPGA芯片,无法加密怎么搞?
我就用DS2401,价格也便宜,占用管脚也少,就一根!
读取也方便,总共也就140行代码module one_wire_controller
#
(
parameter CLK_FREQ = 50000000
)
(
input Clk ,
input Rst ,
inout Dq ,
output [63:0] ReadData,
output reg ReadFinish
);
[payamount]1.00[/payamount]
[pay]
-
- //
- //do read after reset is high
-
- module one_wire_controller
- #
- (
- parameter CLK_FREQ = 50000000
- )
- (
- input Clk , //50M
- input Rst ,
- inout Dq ,
- output [63:0] ReadData,
- output reg ReadFinish
- );
-
-
- localparam ROM_CMD = 8'h33;
- localparam IDLE_STATE = 8'b0000_0001 ,
- RESET = 8'b0000_0010 ,
- READ_PULSE = 8'b0000_0100 ,
- WRITE_ROM_CMD = 8'b0000_1000 ,
- READ_FAMILY_CODE = 8'b0001_0000 ,
- READ_SERINUM_CODE = 8'b0010_0000 ,
- READ_CRC_CODE = 8'b0100_0000 ,
- DATA_EN = 8'b1000_0000 ;
-
-
- `define TIME_2US CLK_FREQ/1000000*2
- `define TIME_10US CLK_FREQ/1000000*10
- `define TIME_70US CLK_FREQ/1000000*70
- `define TIME_90US CLK_FREQ/1000000*90
- `define TIME_100US CLK_FREQ/1000000*100
- `define TIME_500US CLK_FREQ/1000000*500
- `define TIME_600US CLK_FREQ/1000000*600
-
-
-
- reg [7 : 0] St;
- reg SlaveAck ;
- reg [31 : 0] DelayCnt ;
- reg [5 : 0] BitCnt ;
- reg [63 : 0] ReadDataReg;
- reg DqReg ;
- reg ReadEn;
-
-
- assign Dq = ReadEn ? 1'bz : DqReg;
- assign ReadData = ReadDataReg;
- always @(posedge Clk)
- begin
- case( St )
- IDLE_STATE , DATA_EN : begin DqReg <= 1'b1; ReadEn <= 1'b0; end //Dq output
- READ_PULSE : begin DqReg <= 1'b1; ReadEn <= 1'b1; end //Dq input
- RESET : DqReg <= 1'b0; //Dq output
- WRITE_ROM_CMD : begin
- ReadEn <= 1'b0; //Dq output
- if(DelayCnt < `TIME_2US ) DqReg <= 1'b0; //Dq output 0 keep 2us
- else if(DelayCnt < `TIME_90US ) //delay for 90us
- begin
- if(ROM_CMD[BitCnt] == 1) DqReg <= 1'b1;
- else DqReg <= 1'b0;
- end
- else DqReg <= 1'b1;
- end
- READ_FAMILY_CODE,READ_SERINUM_CODE, READ_CRC_CODE :
- begin
- if(DelayCnt < `TIME_2US ) begin DqReg <= 1'b0 ; ReadEn <= 1'b0 ; end //Dq output 0 keep 2us
- else if( DelayCnt == `TIME_10US ) begin ReadDataReg <= {Dq, ReadDataReg[63:1]}; ReadEn <= 1'b1 ; end //at 10us read Dq data
- else if( DelayCnt < `TIME_90US ) ReadEn <= 1'b1 ;
- else begin DqReg <= 1'b1 ; ReadEn <= 1'b0 ; end //Dq is output
- end
- default : begin DqReg <= 1'b1; ReadEn <= 1'b0; end
- endcase
- end
-
-
-
- always @(posedge Clk )
- begin
- case(St)
- RESET : begin
- if(DelayCnt > `TIME_600US ) DelayCnt <= 32'd0; //delay for 600us
- else DelayCnt <= DelayCnt + 32'd1;
- end
- READ_PULSE : begin
- if( DelayCnt >= `TIME_500US ) DelayCnt <= 32'd0; //delay for 500us
- else if( DelayCnt == `TIME_70US ) begin SlaveAck <= Dq ; DelayCnt <= DelayCnt + 32'd1; end//delay for 70us //get slave reponse
- else DelayCnt <= DelayCnt + 32'd1;
- end
- WRITE_ROM_CMD, READ_FAMILY_CODE, READ_CRC_CODE :
- begin
- if(DelayCnt >= `TIME_100US ) //delay for 100us
- begin
- DelayCnt <= 32'd0;
- if( BitCnt == 6'd7 ) BitCnt <= 6'd0;
- else BitCnt <= BitCnt + 6'd1;
- end
- else begin BitCnt <= BitCnt; DelayCnt <= DelayCnt + 32'd1; end
- end
- READ_SERINUM_CODE: begin
- if(DelayCnt >= `TIME_100US )//delay for 100us
- begin
- DelayCnt <= 32'd0;
- if(BitCnt == 6'd47) BitCnt <= 6'd0;
- else BitCnt <= BitCnt + 6'd1;
- end
- else begin BitCnt <= BitCnt; DelayCnt <= DelayCnt + 32'd1; end
- end
- DATA_EN : ReadFinish <= 1'b1;
- default : begin BitCnt <= 6'd0; SlaveAck <= 1'b1; DelayCnt <= 32'd0; ReadFinish <= 1'b0; end
- endcase
- end
-
-
-
-
- always [url=home.php?mod=space&uid=72445]@[/url] (posedge Clk)
- begin
- if( ~Rst ) St <= IDLE_STATE;
- else
- case(St)
- IDLE_STATE : St <= RESET;
- RESET : if( DelayCnt > `TIME_600US ) St <= READ_PULSE; //delay for 600us
- READ_PULSE : begin
- if( DelayCnt >= `TIME_500US ) //delay for 500us
- begin
- if(SlaveAck == 0 ) St <= WRITE_ROM_CMD;
- end
- end
- WRITE_ROM_CMD : if( ( DelayCnt >= `TIME_100US ) && ( BitCnt == 6'd7 ) ) St <= READ_FAMILY_CODE ;
- READ_FAMILY_CODE : if( ( DelayCnt >= `TIME_100US ) && ( BitCnt == 6'd7 ) ) St <= READ_SERINUM_CODE ;
- READ_SERINUM_CODE : if( ( DelayCnt >= `TIME_100US ) && ( BitCnt == 6'd47) ) St <= READ_CRC_CODE ;
- READ_CRC_CODE : if( ( DelayCnt >= `TIME_100US ) && ( BitCnt == 6'd7 ) ) St <= DATA_EN ;
- default : ;
- endcase
- end
-
-
- endmodule
-
-
-
-
[/pay]
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