📄 i2c_top.v
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////////////////////////////////////////////////////////////////////////////////
// __ ___ _ ___ ____ //
// \ \ / (_) |__ ___ ___|_ _/ ___| //
// \ \ / /| | '_ \ / _ \/ __|| | | //
// \ V / | | |_) | __/\__ \| | |___ //
// \_/ |_|_.__/ \___||___/___\____| //
// //
////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2003-2006 VibesIC, Inc. All rights reserved. //
//----------------------------------------------------------------------------//
// This source code is provided by VibesIC,and be verified on VibesIC FPGA //
// development kit. The source code may be used and distributed without //
// restriction provided that this copyright statement is not removed from the //
// file and that any derivative work contains the original copyright notice //
// and the associated disclaimer. //
//----------------------------------------------------------------------------//
// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED //
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// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. //
//----------------------------------------------------------------------------//
// 本设计由威百仕( VibesIC )提供，并在其产品中验证通过，您可以在此基础上修改，//
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////////////////////////////////////////////////////////////////////////////////
// Company: www.richic.com //
// Company bbs: www.edacn.net //
// Engineer: alex_yang //
// //
// Target Device: XC3S400-PQ208 //
// Tool versions: Simulation: ModelSim SE 6.2a //
// Synthesis: XST(ise8.1...sp3) //
// Place&Routing: ISE8.1...sp3 //
// Others tools: UltraEdit-32 12.10a //
// Create Date: 2006-12-21 14:19 //
// Description: //
// //
// LOG: //
// 1. Revision 1.0 (Initial version) 2006-12-21 14:19 alex_yang //
// //
// 2. Revision 1.1 2006-12-26 9:11 alex_yang //
// Modify for VX-SP306 //
////////////////////////////////////////////////////////////////////////////////
`timescale 1ns/1ns
module i2c_top(clk, rst_n, sda, scl, hc_cp, hc_si);
input clk;
input rst_n;
inout sda;
output scl;
output hc_cp;
output hc_si;
reg wr; //write eeprom command
reg rd; //read eeprom command
reg [10:0] addr; //write or read address.
reg [7:0] data_w; //write data to eeprom
wire ack; //i2c write or read complete
wire [7:0] data_r; //read data from eeprom
reg [15:0] data_rep; //存储显示在七段数码管上的数据
reg show_ok; //正确显示后的标志
reg wr_flag; //记录是否已经发送过write,read command
reg [6:0] cs,ns;
parameter IDLE = 7'b0000001,
WR_BYTE = 7'b0000010,
WR_ACK = 7'b0000100,
DELAY = 7'B0001000,
RD_BYTE = 7'b0010000,
RD_ACK = 7'b0100000,
SHOW = 7'b1000000;
//-------------产生时钟clk分频-----------------------------------------------
reg [11:0] clk_cnt;
reg [12:0] clk_div_cnt;
reg clk_div;
always @ (posedge clk or negedge rst_n)
if (!rst_n)
clk_cnt <= 12'd0;
else if (clk_cnt == 12'd1250) //get 20khz SCL clock
clk_cnt <= 12'd0;
else
clk_cnt <= clk_cnt + 1'b1;
always @ (posedge clk or negedge rst_n)
if (!rst_n)
clk_div <= 1'b0;
else if (clk_cnt == 12'd1250)
clk_div <= ~clk_div; //20khz
always @ (posedge clk_div or negedge rst_n)
if (!rst_n)
clk_div_cnt <= 13'd0;
else
clk_div_cnt <= clk_div_cnt + 1'b1;
//---------State machine------------------
always @ (posedge clk_div or negedge rst_n)
if (!rst_n)
cs <= IDLE;
else
cs <= ns;
always @ ( * )
case (cs)
IDLE:
if (clk_div_cnt == 13'd1000)
ns = WR_BYTE;
else
ns = IDLE;
WR_BYTE:
if (ack)
ns = WR_ACK;
else
ns = WR_BYTE;
WR_ACK:
if (!ack)
ns = DELAY;
else
ns = WR_ACK;
DELAY://eeprom写数据需要时间(请参考SPEC),故：等待数据写完后再进行读操作
if (clk_div_cnt == 13'd1300)
ns = RD_BYTE;
else
ns = DELAY;
RD_BYTE:
if (ack)
ns = RD_ACK;
else
ns = RD_BYTE;
RD_ACK:
if (!ack)
ns = SHOW;
else
ns = RD_ACK;
SHOW:
if (show_ok)
ns = IDLE;
else
ns = SHOW;
default:
ns = IDLE;
endcase
always @ (posedge clk_div or negedge rst_n)
if (!rst_n)
begin
wr <= 1'b0;
rd <= 1'b0;
addr <= 11'd0;
data_w <= 8'd0;
// data_w <= 8'h58;
show_ok <= 1'b0;
wr_flag <= 1'b0;
end
else if (data_w == 8'd255) //计数到255就重新开始
begin
addr <= 11'd0;
data_w <= 8'd0;
// data_w <= 8'h58;
end
else
case (cs)
IDLE:
begin
wr <= 1'b0;
rd <= 1'b0;
show_ok <= 1'b0;
wr_flag <= 1'b0;
end
WR_BYTE:
if (wr_flag == 1'b0)
begin
wr <= 1'b1;
wr_flag <= 1'b1;
end
else
wr <= 1'b0;
WR_ACK:
wr_flag <= 1'b0;
DELAY:
begin
wr <= 1'b0;
rd <= 1'b0;
show_ok <= 1'b0;
wr_flag <= 1'b0;
end
RD_BYTE:
if (wr_flag == 1'b0)
begin
rd <= 1'b1;
wr_flag <= 1'b1;
end
else
rd <= 1'b0;
RD_ACK:
begin
wr_flag <= 1'b0;
show_ok <= 1'b1;
end
SHOW:
begin
show_ok <= 1'b0;
addr <= addr + 1'b1;
data_w <= data_w + 1'b1;
end
default:
begin
wr <= 1'b0;
rd <= 1'b0;
show_ok <= 1'b0;
wr_flag <= 1'b0;
end
endcase
always @ (posedge clk_div or negedge rst_n)
if (!rst_n)
data_rep <=16'h0000;
else if (show_ok)
data_rep <= {data_w,data_r}; //将写入eeprom和从eeprom中读出的数据进行对比输出
// ---------------------------------------------------------------------------
// 例化EEPROM: 24C02的驱动程序
// ---------------------------------------------------------------------------
i2c_wr i2c_wr_inst(
.clk (clk_div),
.rst_n (rst_n),
.wr (wr),
.rd (rd),
.addr (addr),
.data_w (data_w),
.data_r (data_r),
.ack (ack),
.scl (scl),
.sda (sda)
);
// ---------------------------------------------------------------------------
// 例化hc164的驱动程序
// ---------------------------------------------------------------------------
hc164_driver hc164_driver_inst(
.clk ( clk ),
.rst_n ( rst_n ),
.led ( {4{ ack }} ),
.dot ( 4'b0000 ),
.seg_value ( data_rep ),
.hc_cp ( hc_cp ),
.hc_si ( hc_si )
);
endmodule⌨️ 快捷键说明
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