Verilog实现IIC通讯第二版
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发表于 2013/8/14 13:56:52
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HMC5883三轴磁力传感器IIC通讯模块的VerilogHDL的实现
上一版并没有实现我想要的功能
0.0.1版 正在修订中 2013/9/2
//date :2013/7/7
//designer :pengxiaoen
//synthesizer:QuartusII 12.1
//function : IIC实现HMC5883的通讯 50M /(400k × 4)= 32
`define WriteAddress 8'h3c
`define ReadAddress 8'h3d
`define RegAAddress 8'h00 //配置寄存器A
`define RegBAddress 8'h01 //配置寄存器B
`define ModelAddress 8'h02 //模式寄存器
`define X_MSBAddress 8'h03 //X MSB寄存器
`define X_LSBAddress 8'h04
`define Z_MSBAddress 8'h05
`define Z_LSBAddress 8'h06
`define Y_MSBAddress 8'h07
`define Y_LSBAddress 8'h08
`define STATEAddress 8'h09 //状态寄存器
`define IdentifyAAddress 8'h10 //识别寄存器A
`define IdentifyBAddress 8'h10
`define IdentifyCAddress 8'h10
`define INITIAL 0
`define DELAY 1
`define MEASURE 2
`define START 3
`define Re 4
`define Se 5
`define STOP 6
//`default_nettype none
module HMC5883_2 (
clock,reset,
sda,scl,
out_seg,
sel_seg,
IIC_result
);
input clock,reset;
inout sda,scl;
output reg [7:0]out_seg;
output reg IIC_result;
output reg [5:0]sel_seg;
reg [7:0] SEND_buffer;
reg [7:0] Re_buffer ;
reg sda_reg;
reg scl_reg;
reg ack_reg;
reg sda_enable;
reg scl_enable;
reg IC_state;
reg n_IC_state;
reg [2:0]state; //当前状态寄存器
reg state_finish_flag ; //
reg [5:0] scl_4;
reg [3:0] step_counter;
reg [3:0] clk_temp ;
//==============================================================================================
//-------------时钟控制模块------------------start---------------
always @ (posedge clock or negedge reset)
if (!reset)
begin
clk_temp <= 4'd0;
scl_4 <= 6'd0;
end
else if (clk_temp==4'd15)
begin
clk_temp <= 4'd0;
if (state_finish_flag) scl_4 <= 6'd0;
else if (scl_4 == 6'b111_111) //这里是一个保护机制，可以设置一个flag
scl_4 <= 6'b111_111;
else scl_4 <= scl_4 + 1;
end
else clk_temp <= clk_temp + 1;
//----------时钟控制模块----------end-----------
//--------一个检测的pin---------start-----------
always @(posedge clock or negedge reset)
if(!reset)
IIC_result <= 1'd0;
else if(scl_4 == 6'b111_111)
IIC_result <= 1'd1;
else ;
//-----------一个检测的pin-------end----------
//-------延时模块----5us------start--------
reg [7:0] delay_counter;
reg delay_enable;
always @(posedge clock )
if(!delay_enable)
begin
delay_counter <= 8'd0;
state_finish_flag <= 1'd0;
end
else if(delay_counter == 8'd250)
begin
state_finish_flag <= 1'd1;
delay_counter <= 8'd0;
end
else begin
delay_counter <= delay_counter + 1;
state_finish_flag <= 1'd0;
end
//--------------延时模块-------end---------------
//----------状态机控制模块---------start-------
always @ (posedge clock or negedge reset)
if(!reset)
IC_state <= `INITIAL;
else IC_state <= n_IC_state;
//------------------------------------------
always @ (posedge state_finish_flag or negedge reset)
if (!reset)
begin
SEND_buffer <= 8'd0;
n_IC_state <= 1'd0;
end
else if(IC_state == `INITIAL)
case (step_counter)
0: begin state <= `START;end
1: begin state <= `Se; SEND_buffer <= `WriteAddress; end
2: begin state <= `Se; SEND_buffer <= `ModelAddress; end
3: begin state <= `Se; SEND_buffer <= `RegAAddress; end
4: begin state <= `STOP; end
5: begin n_IC_state <= `MEASURE; end
default state <= `START;
endcase
else if (IC_state == `MEASURE)
case (step_counter)
0: begin state <= `START; end
1: begin state <= `Se; SEND_buffer <= `WriteAddress; end
2: begin state <= `Se; SEND_buffer <= `X_MSBAddress; end
3: begin state <= `START; end
4: begin state <= `Se; SEND_buffer <= `ReadAddress;end
5: begin state <= `Re; end
6: begin state <= `Re; end
7: begin state <= `Re; end
8: begin state <= `Re; end
9: begin state <= `Re; end
10: begin state <= `Re; end
11: begin state <= `STOP; end
12:begin n_IC_state <= `INITIAL; end
default state <= `START;
endcase
else ;
//----------状态机控制模块----------end--- ---
//----------执行步骤计数--------start------------
always @ (posedge clock or negedge reset)
if (!reset) begin
step_counter <= 4'd0; end
else if((IC_state == `INITIAL)&& (state_finish_flag)) begin
if(step_counter == 4'd5) step_counter <= 4'd0;
else step_counter <= step_counter + 1; end
else if((IC_state == `MEASURE) && (state_finish_flag)) begin
if(step_counter == 4'd12 ) step_counter <= 4'd0;
else step_counter <= step_counter + 1; end
else ;
//----------执行步骤计数--------end------------
//-----------外部数据线 控制模块----start------
always @ (posedge clock or negedge reset)
if(!reset)
begin
Re_buffer <= 8'd0;
sda_enable <= 1'd0;
scl_enable <= 1'd0;
delay_enable <= 1'd0;
end
else case (state)
`START : case (scl_4)
0: begin sda_enable <= 1'd1; scl_enable <= 1'd1; delay_enable <= 1'd0;
sda_reg <= 1'd1; scl_reg <= 1'd0; end
1: begin sda_reg <= 1'd1; scl_reg <= 1'd0; end
2: begin sda_reg <= 1'd1; scl_reg <= 1'd1; end
3: begin sda_reg <= 1'd0; scl_reg <= 1'd1; end
4: delay_enable <= 1'd1;
default begin sda_reg <= 1'dz; scl_reg <= 1'dz; end
endcase
`STOP : case (scl_4)
0: begin sda_enable <= 1'd1; scl_enable <= 1'd1; delay_enable <= 1'd0;
sda_reg <= 1'd0; scl_reg <= 1'd0; end
1: begin sda_reg <= 1'd0; scl_reg <= 1'd0; end
2: begin sda_reg <= 1'd0; scl_reg <= 1'd1; end
3: begin sda_reg <= 1'd1; scl_reg <= 1'd1; end
4: delay_enable <= 1'd1;
default begin sda_reg <= 1'dz; scl_reg <= 1'dz; end
endcase
`Se : case (scl_4)
0: begin sda_enable <= 1'd1; scl_enable <= 1'd1; delay_enable <= 1'd0;
sda_reg <= 1'd0; scl_reg <= 1'd0; end
1: begin sda_reg <= SEND_buffer[7]; scl_reg <= 1'd0; end
2: begin sda_reg <= SEND_buffer[7]; scl_reg <= 1'd1; end
3: begin sda_reg <= SEND_buffer[7]; scl_reg <= 1'd1; end
4: begin scl_reg <= 1'd0; end
5: begin sda_reg <= SEND_buffer[6]; scl_reg <= 1'd0; end
6: begin sda_reg <= SEND_buffer[6]; scl_reg <= 1'd1; end
7: begin sda_reg <= SEND_buffer[6]; scl_reg <= 1'd1; end
8: begin scl_reg <= 1'd0; end
9: begin sda_reg <= SEND_buffer[5]; scl_reg <= 1'd0; end
10: begin sda_reg <= SEND_buffer[5]; scl_reg <= 1'd1; end
11: begin sda_reg <= SEND_buffer[5]; scl_reg <= 1'd1; end
12: begin scl_reg <= 1'd0; end
13: begin sda_reg <= SEND_buffer[4]; scl_reg <= 1'd0; end
14: begin sda_reg <= SEND_buffer[4]; scl_reg <= 1'd1; end
15: begin sda_reg <= SEND_buffer[4]; scl_reg <= 1'd1; end
16: begin scl_reg <= 1'd0; end
17: begin sda_reg <= SEND_buffer[3]; scl_reg <= 1'd0; end
18: begin sda_reg <= SEND_buffer[3]; scl_reg <= 1'd1; end
19: begin sda_reg <= SEND_buffer[3]; scl_reg <= 1'd1; end
20: begin scl_reg <= 1'd0; end
21: begin sda_reg <= SEND_buffer[2]; scl_reg <= 1'd0; end
22: begin sda_reg <= SEND_buffer[2]; scl_reg <= 1'd1; end
23: begin sda_reg <= SEND_buffer[2]; scl_reg <= 1'd1; end
24: begin scl_reg <= 1'd0; end
25: begin sda_reg <= SEND_buffer[1]; scl_reg <= 1'd0; end
26: begin sda_reg <= SEND_buffer[1]; scl_reg <= 1'd1; end
27: begin sda_reg <= SEND_buffer[1]; scl_reg <= 1'd1; end
28: begin scl_reg <= 1'd0; end
29: begin sda_reg <= SEND_buffer[0]; scl_reg <= 1'd0; end
30: begin sda_reg <= SEND_buffer[0]; scl_reg <= 1'd1; end
31: begin sda_reg <= SEND_buffer[0]; scl_reg <= 1'd1; end
//此时序之后必须释放掉sda控制权 等待响应
32: begin sda_enable <= 1'd0; scl_enable <= 1'd0; delay_enable <= 1'd1;
ack_reg <= 1'd0; scl_reg <= 1'd0; end //这里出现了一个警告，因为ack_reg没有利用到
33: begin ack_reg <= sda; scl_reg <= 1'd0; end
34: begin ack_reg <= sda; scl_reg <= 1'd1; end
35: begin ack_reg <= sda; scl_reg <= 1'd1; end
//此时IC有可能在一个时钟下来不及响应，从而导致主机没有接收到响应信号
default begin scl_reg <= 1'dz; end
endcase
`Re : case (scl_4)
0: begin sda_enable <= 1'd0; scl_enable <= 1'd1; delay_enable <= 1'd0;
scl_reg <= 1'd0; end
1: begin scl_reg <= 1'd0; end
2: begin scl_reg <= 1'd1; end
3: begin Re_buffer[7] <= sda; scl_reg <= 1'd1; end
4: begin scl_reg <= 1'd0; end
5: begin scl_reg <= 1'd0; end
6: begin scl_reg <= 1'd1; end
7: begin Re_buffer[6] <= sda; scl_reg <= 1'd1; end
8: begin scl_reg <= 1'd0; end
9: begin scl_reg <= 1'd0; end
10: begin scl_reg <= 1'd1; end
11: begin Re_buffer[5] <= sda; scl_reg <= 1'd1; end
12: begin scl_reg <= 1'd0; end
13: begin scl_reg <= 1'd0; end
14: begin scl_reg <= 1'd1; end
15: begin Re_buffer[4] <= sda; scl_reg <= 1'd1; end
16: begin scl_reg <= 1'd0; end
17: begin scl_reg <= 1'd0; end
18: begin scl_reg <= 1'd1; end
19: begin Re_buffer[3] <= sda; scl_reg <= 1'd1; end
20: begin scl_reg <= 1'd0; end
21: begin scl_reg <= 1'd0; end
22: begin scl_reg <= 1'd1; end
23: begin Re_buffer[2] <= sda; scl_reg <= 1'd1; end
24: begin scl_reg <= 1'd0; end
25: begin scl_reg <= 1'd0; end
26: begin scl_reg <= 1'd1; end
27: begin Re_buffer[1] <= sda; scl_reg <= 1'd1; end
28: begin scl_reg <= 1'd0; end
29: begin scl_reg <= 1'd0; end
30: begin scl_reg <= 1'd1; end
31: begin Re_buffer[0] <= sda; scl_reg <= 1'd1; end
//此时序之后主机夺回sda控制权,延时开始
32: begin sda_enable <= 1'd1; delay_enable <= 1'd1;
sda_reg <= 0; scl_reg <= 1'd0; end
33: begin sda_reg <= 0; scl_reg <= 1'd0; end
34: begin sda_reg <= 0; scl_reg <= 1'd1; end
35: begin sda_reg <= 0; scl_reg <= 1'd1; end
default begin sda_reg <= 1'dz; scl_reg <= 1'dz;end
endcase
endcase
//-------外部数据线 控制模块----------end---------------
assign sda = sda_enable ? sda_reg : 1'dz ;
assign scl = scl_enable ? scl_reg : 1'dz ;
//====================================================================================
//--------------数码管显示部分=======只显示了一部分，有待优化============================
always @ ( posedge clock or negedge reset)
if (!reset)
begin
sel_seg <= 6'b111110;
end
else if(state_finish_flag)
begin
sel_seg <= {sel_seg[4:0],sel_seg[5]};
end
//------------------------------------------------
always @(posedge clock or negedge reset)
if (!reset) out_seg <= 8'd0;
else
begin
case (Re_buffer[3:0]) //刚开始这里没有[3：0] 居然没有报错，连个警告都没有，这是为什么呢
4'b0000 : out_seg<=8'b1100_0000;//0000_0011
4'b0001 : out_seg<=8'b1111_1001;//1001_1111
4'b0010 : out_seg<=8'b1010_0100;//0010_0101
4'b0011 : out_seg<=8'b1011_0000;//0000_1101
4'b0100 : out_seg<=8'b1001_1001;//1001_1001
4'b0101 : out_seg<=8'b1001_0010;//0100_1001
4'b0110 : out_seg<=8'b1000_0010;//0100_0001
4'b0111 : out_seg<=8'b1111_1000;//0001_1111
4'b1000 : out_seg<=8'b1000_0000;//0000_0001
4'b1001 : out_seg<=8'b1001_1000;//0001_1001
4'b1010 : out_seg<=8'b1000_1000;//0001_0001
4'b1011 : out_seg<=8'b1000_0011;//1100_0001
4'b1100 : out_seg<=8'b1100_0110;//0110_0011
4'b1101 : out_seg<=8'b1010_0001;//1000_0101
4'b1110 : out_seg<=8'b1000_0110;//0110_0001
4'b1111 : out_seg<=8'b1000_1110;//0111_0001
endcase
end
//-------------------------------=================================
endmodule
