日常·唠嗑
IIC协议这里就不赘述了，网上很多，这里推荐两个，可以看看【接口时序】6、IIC总线的原理与Verilog实现 ，还有IIC协议原理以及主机、从机Verilog实现。
前者是对IIC协议详细介绍、以及主机发送，主机接收两种方式。后者，是在前者基础上做设计，讲的是主机、从机两种设计实例。关于IIC从机，网上例程较少，可以参考这个博主的。不过，这个博主的状态机写的很乱，也没什么注释，看了两天才搞明白Verilog描述的什么，如果有FPGA爱好者需要用到，又看不懂的，可以私信我：bumianzhe@126.com.
一、程序设计
本程序参考芯路恒IIC设计，可以去他们官网下完整资料看看。
顶层模块：用来控制底层模块连续读写，包含了状态机
module i2c_control(
Clk,
Rst_n,
wrreg_req,
rdreg_req,
addr,
addr_mode,
wrdata,
rddata,
device_id,
RW_Done,
ack,
i2c_sclk,
i2c_sdat
);
input Clk;
input Rst_n;
input wrreg_req;
input rdreg_req;
input [15:0]addr;
input addr_mode;
input [7:0]wrdata;
output reg[7:0]rddata;
input [7:0]device_id;
output reg RW_Done;
output reg ack;
output i2c_sclk;
inout i2c_sdat;
reg [5:0]Cmd;
reg [7:0]Tx_DATA;
wire Trans_Done;
wire ack_o;
reg Go;
wire [15:0] reg_addr;
assign reg_addr = addr_mode?addr:{addr[7:0],addr[15:8]};
wire [7:0]Rx_DATA;
localparam
WR = 6'b000001, //写请求
STA = 6'b000010, //起始位请求
RD = 6'b000100, //读请求
STO = 6'b001000, //停止位请求
ACK = 6'b010000, //应答位请求
NACK = 6'b100000; //无应答请求
i2c_bit_shift i2c_bit_shift(
.Clk(Clk),
.Rst_n(Rst_n),
.Cmd(Cmd),
.Go(Go),
.Rx_DATA(Rx_DATA),
.Tx_DATA(Tx_DATA),
.Trans_Done(Trans_Done),
.ack_o(ack_o),
.i2c_sclk(i2c_sclk),
.i2c_sdat(i2c_sdat)
);
reg [6:0]state;
reg [7:0]cnt;
localparam
IDLE = 7'b0000001, //空闲状态
WR_REG = 7'b0000010, //写寄存器状态
WAIT_WR_DONE = 7'b0000100, //等待写寄存器完成状态
WR_REG_DONE = 7'b0001000, //写寄存器完成状态
RD_REG = 7'b0010000, //读寄存器状态
WAIT_RD_DONE = 7'b0100000, //等待读寄存器完成状态
RD_REG_DONE = 7'b1000000; //读寄存器完成状态
always@(posedge Clk or negedge Rst_n)
if(!Rst_n)begin
Cmd <= 6'd0;
Tx_DATA <= 8'd0;
Go <= 1'b0;
rddata <= 0;
state <= IDLE;
ack <= 0;
end
else begin
case(state)
IDLE:
begin
cnt <= 0;
ack <= 0;
RW_Done <= 1'b0;
if(wrreg_req)
state <= WR_REG;
else if(rdreg_req)
state <= RD_REG;
else
state <= IDLE;
end
WR_REG:
begin
state <= WAIT_WR_DONE;
case(cnt)
0:write_byte(WR | STA, device_id);
1:write_byte(WR, reg_addr[15:8]);
2:write_byte(WR, reg_addr[7:0]);
3:write_byte(WR | STO, wrdata);
default:;
endcase
end
WAIT_WR_DONE:
begin
Go <= 1'b0;
if(Trans_Done)begin
ack <= ack | ack_o;
case(cnt)
0: begin cnt <= 1; state <= WR_REG;end
1:
begin
state <= WR_REG;
if(addr_mode)
cnt <= 2;
else
cnt <= 3;
end
2: begin
cnt <= 3;
state <= WR_REG;
end
3:state <= WR_REG_DONE;
default:state <= IDLE;
endcase
end
end
WR_REG_DONE:
begin
RW_Done <= 1'b1;
state <= IDLE;
end
RD_REG:
begin
state <= WAIT_RD_DONE;
case(cnt)
0:write_byte(WR | STA, device_id);
1:write_byte(WR, reg_addr[15:8]);
2:write_byte(WR, reg_addr[7:0]);
3:write_byte(WR | STA, device_id | 8'd1);
4:read_byte(RD | NACK | STO);
default:;
endcase
end
WAIT_RD_DONE:
begin
Go <= 1'b0;
if(Trans_Done)begin
if(cnt <= 3)
ack <= ack | ack_o;
case(cnt)
0: begin cnt <= 1; state <= RD_REG;end
1:
begin
state <= RD_REG;
if(addr_mode)
cnt <= 2;
else
cnt <= 3;
end
2: begin
cnt <= 3;
state <= RD_REG;
end
3:begin
cnt <= 4;
state <= RD_REG;
end
4:state <= RD_REG_DONE;
default:state <= IDLE;
endcase
end
end
RD_REG_DONE:
begin
RW_Done <= 1'b1;
rddata <= Rx_DATA;
state <= IDLE;
end
default:state <= IDLE;
endcase
end
task read_byte;
input [5:0]Ctrl_Cmd;
begin
Cmd <= Ctrl_Cmd;
Go <= 1'b1;
end
endtask
task write_byte;
input [5:0]Ctrl_Cmd;
input [7:0]Wr_Byte_Data;
begin
Cmd <= Ctrl_Cmd;
Tx_DATA <= Wr_Byte_Data;
Go <= 1'b1;
end
endtask
endmodule
子模块：单字节读写操作
module i2c_bit_shift(
Clk,
Rst_n,
Cmd,
Go,
Rx_DATA,
Tx_DATA,
Trans_Done,
ack_o,
i2c_sclk,
i2c_sdat
);
input Clk;
input Rst_n;
input [5:0]Cmd;
input Go;
output reg[7:0]Rx_DATA;
input [7:0]Tx_DATA;
output reg Trans_Done;
output reg ack_o;
output reg i2c_sclk;
inout i2c_sdat;
reg i2c_sdat_o;
//系统时钟采用50MHz
parameter SYS_CLOCK = 50_000_000;
//SCL总线时钟采用400kHz
parameter SCL_CLOCK = 400_000;
//产生时钟SCL计数器最大值
localparam SCL_CNT_M = SYS_CLOCK/SCL_CLOCK/4 - 1;
reg i2c_sdat_oe;
localparam
WR = 6'b000001, //写请求
STA = 6'b000010, //起始位请求
RD = 6'b000100, //读请求
STO = 6'b001000, //停止位请求
ACK = 6'b010000, //应答位请求
NACK = 6'b100000; //无应答请求
reg [19:0]div_cnt;
reg en_div_cnt;
always@(posedge Clk or negedge Rst_n)
if(!Rst_n)
div_cnt <= 20'd0;
else if(en_div_cnt)begin
if(div_cnt < SCL_CNT_M)
div_cnt <= div_cnt + 1'b1;
else
div_cnt <= 0;
end
else
div_cnt <= 0;
wire sclk_plus = div_cnt == SCL_CNT_M;
//assign i2c_sdat = i2c_sdat_oe?i2c_sdat_o:1'bz;
assign i2c_sdat = !i2c_sdat_o && i2c_sdat_oe ? 1'b0:1'bz;
reg [7:0]state;
localparam
IDLE = 8'b00000001, //空闲状态
GEN_STA = 8'b00000010, //产生起始信号
WR_DATA = 8'b00000100, //写数据状态
RD_DATA = 8'b00001000, //读数据状态
CHECK_ACK = 8'b00010000, //检测应答状态
GEN_ACK = 8'b00100000, //产生应答状态
GEN_STO = 8'b01000000; //产生停止信号
reg [4:0]cnt;
always@(posedge Clk or negedge Rst_n)
if(!Rst_n)begin
Rx_DATA <= 0;
i2c_sdat_oe <= 1'd0;
en_div_cnt <= 1'b0;
i2c_sdat_o <= 1'd1;
Trans_Done <= 1'b0;
ack_o <= 0;
state <= IDLE;
cnt <= 0;
end
else begin
case(state)
IDLE:
begin
Trans_Done <= 1'b0;
i2c_sdat_oe <= 1'd1;
if(Go)begin
en_div_cnt <= 1'b1;
if(Cmd & STA)
state <= GEN_STA;
else if(Cmd & WR)
state <= WR_DATA;
else if(Cmd & RD)
state <= RD_DATA;
else
state <= IDLE;
end
else begin
en_div_cnt <= 1'b0;
state <= IDLE;
end
end
GEN_STA:
begin
if(sclk_plus)begin
if(cnt == 3)
cnt <= 0;
else
cnt <= cnt + 1'b1;
case(cnt)
0:begin i2c_sdat_o <= 1; i2c_sdat_oe <= 1'd1;end
1:begin i2c_sclk <= 1;end
2:begin i2c_sdat_o <= 0; i2c_sclk <= 1;end
3:begin i2c_sclk <= 0;end
default:begin i2c_sdat_o <= 1; i2c_sclk <= 1;end
endcase
if(cnt == 3)begin
if(Cmd & WR)
state <= WR_DATA;
else if(Cmd & RD)
state <= RD_DATA;
end
end
end
WR_DATA:
begin
if(sclk_plus)begin
if(cnt == 31)
cnt <= 0;
else
cnt <= cnt + 1'b1;
case(cnt)
0,4,8,12,16,20,24,28:begin i2c_sdat_o <= Tx_DATA[7-cnt[4:2]]; i2c_sdat_oe <= 1'd1;end //set data;
1,5,9,13,17,21,25,29:begin i2c_sclk <= 1;end //sclk posedge
2,6,10,14,18,22,26,30:begin i2c_sclk <= 1;end //sclk keep high
3,7,11,15,19,23,27,31:begin i2c_sclk <= 0;end //sclk negedge
/*
0 :begin i2c_sdat_o <= Tx_DATA[7];end
1 :begin i2c_sclk <= 1;end //sclk posedge
2 :begin i2c_sclk <= 1;end //sclk keep high
3 :begin i2c_sclk <= 0;end //sclk negedge
4 :begin i2c_sdat_o <= Tx_DATA[6];end
5 :begin i2c_sclk <= 1;end //sclk posedge
6 :begin i2c_sclk <= 1;end //sclk keep high
7 :begin i2c_sclk <= 0;end //sclk negedge
8 :begin i2c_sdat_o <= Tx_DATA[5];end
9 :begin i2c_sclk <= 1;end //sclk posedge
10:begin i2c_sclk <= 1;end //sclk keep high
11:begin i2c_sclk <= 0;end //sclk negedge
12:begin i2c_sdat_o <= Tx_DATA[4];end
13:begin i2c_sclk <= 1;end //sclk posedge
14:begin i2c_sclk <= 1;end //sclk keep high
15:begin i2c_sclk <= 0;end //sclk negedge
16:begin i2c_sdat_o <= Tx_DATA[3];end
17:begin i2c_sclk <= 1;end //sclk posedge
18:begin i2c_sclk <= 1;end //sclk keep high
19:begin i2c_sclk <= 0;end //sclk negedge
20:begin i2c_sdat_o <= Tx_DATA[2];end
21:begin i2c_sclk <= 1;end //sclk posedge
22:begin i2c_sclk <= 1;end //sclk keep high
23:begin i2c_sclk <= 0;end //sclk negedge
24:begin i2c_sdat_o <= Tx_DATA[1];end
25:begin i2c_sclk <= 1;end //sclk posedge
26:begin i2c_sclk <= 1;end //sclk keep high
27:begin i2c_sclk <= 0;end //sclk negedge
28:begin i2c_sdat_o <= Tx_DATA[0];end
29:begin i2c_sclk <= 1;end //sclk posedge
30:begin i2c_sclk <= 1;end //sclk keep high
31:begin i2c_sclk <= 0;end //sclk negedge
*/
default:begin i2c_sdat_o <= 1; i2c_sclk <= 1;end
endcase
if(cnt == 31)begin
state <= CHECK_ACK;
end
end
end
RD_DATA:
begin
if(sclk_plus)begin
if(cnt == 31)
cnt <= 0;
else
cnt <= cnt + 1'b1;
case(cnt)
0,4,8,12,16,20,24,28:begin i2c_sdat_oe <= 1'd0; i2c_sclk <= 0;end //set data;
1,5,9,13,17,21,25,29:begin i2c_sclk <= 1;end //sclk posedge
2,6,10,14,18,22,26,30:begin i2c_sclk <= 1; Rx_DATA <= {Rx_DATA[6:0],i2c_sdat};end //sclk keep high
3,7,11,15,19,23,27,31:begin i2c_sclk <= 0;end //sclk negedge
default:begin i2c_sdat_o <= 1; i2c_sclk <= 1;end
endcase
if(cnt == 31)begin
state <= GEN_ACK;
end
end
end
CHECK_ACK:
begin
if(sclk_plus)begin
if(cnt == 3)
cnt <= 0;
else
cnt <= cnt + 1'b1;
case(cnt)
0:begin i2c_sdat_oe <= 1'd0; i2c_sclk <= 0;end
1:begin i2c_sclk <= 1;end
2:begin ack_o <= i2c_sdat; i2c_sclk <= 1;end
3:begin i2c_sclk <= 0;end
default:begin i2c_sdat_o <= 1; i2c_sclk <= 1;end
endcase
if(cnt == 3)begin
if(Cmd & STO)
state <= GEN_STO;
else begin
state <= IDLE;
Trans_Done <= 1'b1;
end
end
end
end
GEN_ACK:
begin
if(sclk_plus)begin
if(cnt == 3)
cnt <= 0;
else
cnt <= cnt + 1'b1;
case(cnt)
0:begin
i2c_sdat_oe <= 1'd1;
i2c_sclk <= 0;
if(Cmd & ACK)
i2c_sdat_o <= 1'b0;
else if(Cmd & NACK)
i2c_sdat_o <= 1'b1;
end
1:begin i2c_sclk <= 1;end
2:begin i2c_sclk <= 1;end
3:begin i2c_sclk <= 0;end
default:begin i2c_sdat_o <= 1; i2c_sclk <= 1;end
endcase
if(cnt == 3)begin
if(Cmd & STO)
state <= GEN_STO;
else begin
state <= IDLE;
Trans_Done <= 1'b1;
end
end
end
end
GEN_STO:
begin
if(sclk_plus)begin
if(cnt == 3)
cnt <= 0;
else
cnt <= cnt + 1'b1;
case(cnt)
0:begin i2c_sdat_o <= 0; i2c_sdat_oe <= 1'd1;end
1:begin i2c_sclk <= 1;end
2:begin i2c_sdat_o <= 1; i2c_sclk <= 1;end
3:begin i2c_sclk <= 1;end
default:begin i2c_sdat_o <= 1; i2c_sclk <= 1;end
endcase
if(cnt == 3)begin
Trans_Done <= 1'b1;
state <= IDLE;
end
end
end
default:state <= IDLE;
endcase
end
endmodule
二、镁光模型仿真验证
镁 光 官 网 提 供 的 EEPROM 仿 真 模 型 ， 具 体 下 载 网 址 为 ：
http://ww1.microchip.com/downloads/en/DeviceDoc/24xx04_Verilog_Model.zip
1、本次使用的是1 字节寄存器地址段的 24LC04B 仿真模型，进行验证
// *******************************************************************************************************
// ** **
// ** 24LC04B.v - Microchip 24LC04B 4K-BIT I2C SERIAL EEPROM (VCC = +2.5V TO +5.5V) **
// ** **
// *******************************************************************************************************
// ** **
// ** This information is distributed under license from Young Engineering. **
// ** COPYRIGHT (c) 2003 YOUNG ENGINEERING **
// ** ALL RIGHTS RESERVED **
// ** **
// ** **
// ** Young Engineering provides design expertise for the digital world **
// ** Started in 1990, Young Engineering offers products and services for your electronic design **
// ** project. We have the expertise in PCB, FPGA, ASIC, firmware, and software design. **
// ** From concept to prototype to production, we can help you. **
// ** **
// ** http://www.young-engineering.com/ **
// ** **
// *******************************************************************************************************
// ** This information is provided to you for your convenience and use with Microchip products only. **
// ** Microchip disclaims all liability arising from this information and its use. **
// ** **
// ** THIS INFORMATION IS PROVIDED "AS IS." MICROCHIP MAKES NO REPRESENTATION OR WARRANTIES OF **
// ** ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO **
// ** THE INFORMATION PROVIDED TO YOU, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, **
// ** PERFORMANCE, MERCHANTABILITY, NON-INFRINGEMENT, OR FITNESS FOR PURPOSE. **
// ** MICROCHIP IS NOT LIABLE, UNDER ANY CIRCUMSTANCES, FOR SPECIAL, INCIDENTAL OR CONSEQUENTIAL **
// ** DAMAGES, FOR ANY REASON WHATSOEVER. **
// ** **
// ** It is your responsibility to ensure that your application meets with your specifications. **
// ** **
// *******************************************************************************************************
// ** Revision : 1.3 **
// ** Modified Date : 12/04/2006 **
// ** Revision History: **
// ** **
// ** 02/01/2003: Initial design **
// ** 07/19/2004: Fixed the timing checks and the open-drain modeling for SDA. **
// ** 01/06/2006: Changed the legal information in the header **
// ** 12/04/2006: Corrected timing checks to reference proper clock edges **
// ** Added timing check for Tbuf (bus free time) **
// ** **
// *******************************************************************************************************
// ** TABLE OF CONTENTS **
// *******************************************************************************************************
// **---------------------------------------------------------------------------------------------------**
// ** DECLARATIONS **
// **---------------------------------------------------------------------------------------------------**
// **---------------------------------------------------------------------------------------------------**
// ** INITIALIZATION **
// **---------------------------------------------------------------------------------------------------**
// **---------------------------------------------------------------------------------------------------**
// ** CORE LOGIC **
// **---------------------------------------------------------------------------------------------------**
// ** 1.01: START Bit Detection **
// ** 1.02: STOP Bit Detection **
// ** 1.03: Input Shift Register **
// ** 1.04: Input Bit Counter **
// ** 1.05: Control Byte Register **
// ** 1.06: Byte Address Register **
// ** 1.07: Write Data Buffer **
// ** 1.08: Acknowledge Generator **
// ** 1.09: Acknowledge Detect **
// ** 1.10: Write Cycle Timer **
// ** 1.11: Write Cycle Processor **
// ** 1.12: Read Data Multiplexor **
// ** 1.13: Read Data Processor **
// ** 1.14: SDA Data I/O Buffer **
// ** **
// **---------------------------------------------------------------------------------------------------**
// ** DEBUG LOGIC **
// **---------------------------------------------------------------------------------------------------**
// ** 2.01: Memory Data Bytes **
// ** 2.02: Write Data Buffer **
// ** **
// **---------------------------------------------------------------------------------------------------**
// ** TIMING CHECKS **
// **---------------------------------------------------------------------------------------------------**
// ** **
// *******************************************************************************************************
`timescale 1ns/10ps
module M24LC04B (A0, A1, A2, WP, SDA, SCL, RESET);
input A0; // unconnected pin
input A1; // unconnected pin
input A2; // unconnected pin
input WP; // write protect pin
inout SDA; // serial data I/O
input SCL; // serial data clock
input RESET; // system reset
// *******************************************************************************************************
// ** DECLARATIONS **
// *******************************************************************************************************
reg SDA_DO; // serial data - output
reg SDA_OE; // serial data - output enable
wire SDA_DriveEnable; // serial data output enable
reg SDA_DriveEnableDlyd; // serial data output enable - delayed
wire [02:00] ChipAddress; // hardwired chip address
reg [03:00] BitCounter; // serial bit counter
reg START_Rcvd; // START bit received flag
reg STOP_Rcvd; // STOP bit received flag
reg CTRL_Rcvd; // control byte received flag
reg ADDR_Rcvd; // byte address received flag
reg MACK_Rcvd; // master acknowledge received flag
reg WrCycle; // memory write cycle
reg RdCycle; // memory read cycle
reg [07:00] ShiftRegister; // input data shift register
reg [07:00] ControlByte; // control byte register
wire BlockSelect; // memory block select
wire RdWrBit; // read/write control bit
reg [08:00] StartAddress; // memory access starting address
reg [03:00] PageAddress; // memory page address
reg [07:00] WrDataByte [0:15]; // memory write data buffer
wire [07:00] RdDataByte; // memory read data
reg [15:00] WrCounter; // write buffer counter
reg [03:00] WrPointer; // write buffer pointer
reg [08:00] RdPointer; // read address pointer
reg WriteActive; // memory write cycle active
reg [07:00] MemoryBlock0 [0:255]; // EEPROM data memory array
reg [07:00] MemoryBlock1 [0:255]; // EEPROM data memory array
integer LoopIndex; // iterative loop index
integer tAA; // timing parameter
integer tWC; // timing parameter
// *******************************************************************************************************
// ** INITIALIZATION **
// *******************************************************************************************************
initial tAA = 900; // SCL to SDA output delay
initial tWC = 5000000; // memory write cycle time
initial begin
SDA_DO = 0;
SDA_OE = 0;
end
initial begin
START_Rcvd = 0;
STOP_Rcvd = 0;
CTRL_Rcvd = 0;
ADDR_Rcvd = 0;
MACK_Rcvd = 0;
end
initial begin
BitCounter = 0;
ControlByte = 0;
end
initial begin
WrCycle = 0;
RdCycle = 0;
WriteActive = 0;
end
assign ChipAddress = {A2,A1,A0};
// *******************************************************************************************************
// ** CORE LOGIC **
// *******************************************************************************************************
// -------------------------------------------------------------------------------------------------------
// 1.01: START Bit Detection
// -------------------------------------------------------------------------------------------------------
always @(negedge SDA) begin
if (SCL == 1) begin
START_Rcvd <= 1;
STOP_Rcvd <= 0;
CTRL_Rcvd <= 0;
ADDR_Rcvd <= 0;
MACK_Rcvd <= 0;
WrCycle <= #1 0;
RdCycle <= #1 0;
BitCounter <= 0;
end
end
// -------------------------------------------------------------------------------------------------------
// 1.02: STOP Bit Detection
// -------------------------------------------------------------------------------------------------------
always @(posedge SDA) begin
if (SCL == 1) begin
START_Rcvd <= 0;
STOP_Rcvd <= 1;
CTRL_Rcvd <= 0;
ADDR_Rcvd <= 0;
MACK_Rcvd <= 0;
WrCycle <= #1 0;
RdCycle <= #1 0;
BitCounter <= 10;
end
end
// -------------------------------------------------------------------------------------------------------
// 1.03: Input Shift Register
// -------------------------------------------------------------------------------------------------------
always @(posedge SCL) begin
ShiftRegister[00] <= SDA;
ShiftRegister[01] <= ShiftRegister[00];
ShiftRegister[02] <= ShiftRegister[01];
ShiftRegister[03] <= ShiftRegister[02];
ShiftRegister[04] <= ShiftRegister[03];
ShiftRegister[05] <= ShiftRegister[04];
ShiftRegister[06] <= ShiftRegister[05];
ShiftRegister[07] <= ShiftRegister[06];
end
// -------------------------------------------------------------------------------------------------------
// 1.04: Input Bit Counter
// -------------------------------------------------------------------------------------------------------
always @(posedge SCL) begin
if (BitCounter < 10) BitCounter <= BitCounter + 1;
end
// -------------------------------------------------------------------------------------------------------
// 1.05: Control Byte Register
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (START_Rcvd & (BitCounter == 8)) begin
if (!WriteActive & (ShiftRegister[07:01] == {4'b1010,ChipAddress[02:00]})) begin
if (ShiftRegister[00] == 0) WrCycle <= 1;
if (ShiftRegister[00] == 1) RdCycle <= 1;
ControlByte <= ShiftRegister[07:00];
CTRL_Rcvd <= 1;
end
START_Rcvd <= 0;
end
end
assign BlockSelect = ControlByte[01];
assign RdWrBit = ControlByte[00];
// -------------------------------------------------------------------------------------------------------
// 1.06: Byte Address Register
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (CTRL_Rcvd & (BitCounter == 8)) begin
if (RdWrBit == 0) begin
StartAddress <= {BlockSelect,ShiftRegister[07:00]};
RdPointer <= {BlockSelect,ShiftRegister[07:00]};
ADDR_Rcvd <= 1;
end
WrCounter <= 0;
WrPointer <= 0;
CTRL_Rcvd <= 0;
end
end
// -------------------------------------------------------------------------------------------------------
// 1.07: Write Data Buffer
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (ADDR_Rcvd & (BitCounter == 8)) begin
if ((WP == 0) & (RdWrBit == 0)) begin
WrDataByte[WrPointer] <= ShiftRegister[07:00];
WrCounter <= WrCounter + 1;
WrPointer <= WrPointer + 1;
end
end
end
// -------------------------------------------------------------------------------------------------------
// 1.08: Acknowledge Generator
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (!WriteActive) begin
if (BitCounter == 8) begin
if (WrCycle | (START_Rcvd & (ShiftRegister[07:01] == {4'b1010,ChipAddress[02:00]}))) begin
SDA_DO <= 0;
SDA_OE <= 1;
end
end
if (BitCounter == 9) begin
BitCounter <= 0;
if (!RdCycle) begin
SDA_DO <= 0;
SDA_OE <= 0;
end
end
end
end
// -------------------------------------------------------------------------------------------------------
// 1.09: Acknowledge Detect
// -------------------------------------------------------------------------------------------------------
always @(posedge SCL) begin
if (RdCycle & (BitCounter == 8)) begin
if ((SDA == 0) & (SDA_OE == 0)) MACK_Rcvd <= 1;
end
end
always @(negedge SCL) MACK_Rcvd <= 0;
// -------------------------------------------------------------------------------------------------------
// 1.10: Write Cycle Timer
// -------------------------------------------------------------------------------------------------------
always @(posedge STOP_Rcvd) begin
if (WrCycle & (WP == 0) & (WrCounter > 0)) begin
WriteActive = 1;
#(tWC);
WriteActive = 0;
end
end
always @(posedge STOP_Rcvd) begin
#(1.0);
STOP_Rcvd = 0;
end
// -------------------------------------------------------------------------------------------------------
// 1.11: Write Cycle Processor
// -------------------------------------------------------------------------------------------------------
always @(negedge WriteActive) begin
for (LoopIndex = 0; LoopIndex < WrCounter; LoopIndex = LoopIndex + 1) begin
if (StartAddress[08] == 0) begin
PageAddress = StartAddress[03:00] + LoopIndex;
MemoryBlock0[{StartAddress[07:04],PageAddress[03:00]}] = WrDataByte[LoopIndex[03:00]];
end
if (StartAddress[08] == 1) begin
PageAddress = StartAddress[03:00] + LoopIndex;
MemoryBlock1[{StartAddress[07:04],PageAddress[03:00]}] = WrDataByte[LoopIndex[03:00]];
end
end
end
// -------------------------------------------------------------------------------------------------------
// 1.12: Read Data Multiplexor
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (BitCounter == 8) begin
if (WrCycle & ADDR_Rcvd) begin
RdPointer <= StartAddress + WrPointer + 1;
end
if (RdCycle) begin
RdPointer <= RdPointer + 1;
end
end
end
assign RdDataByte = RdPointer[08] ? MemoryBlock1[RdPointer[07:00]] : MemoryBlock0[RdPointer[07:00]];
// -------------------------------------------------------------------------------------------------------
// 1.13: Read Data Processor
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (RdCycle) begin
if (BitCounter == 8) begin
SDA_DO <= 0;
SDA_OE <= 0;
end
else if (BitCounter == 9) begin
SDA_DO <= RdDataByte[07];
if (MACK_Rcvd) SDA_OE <= 1;
end
else begin
SDA_DO <= RdDataByte[7-BitCounter];
end
end
end
// -------------------------------------------------------------------------------------------------------
// 1.14: SDA Data I/O Buffer
// -------------------------------------------------------------------------------------------------------
bufif1 (SDA, 1'b0, SDA_DriveEnableDlyd);
assign SDA_DriveEnable = !SDA_DO & SDA_OE;
always @(SDA_DriveEnable) SDA_DriveEnableDlyd <= #(tAA) SDA_DriveEnable;
// *******************************************************************************************************
// ** DEBUG LOGIC **
// *******************************************************************************************************
// -------------------------------------------------------------------------------------------------------
// 2.01: Memory Data Bytes
// -------------------------------------------------------------------------------------------------------
wire [07:00] MemoryByte0_00 = MemoryBlock0[00];
wire [07:00] MemoryByte0_01 = MemoryBlock0[01];
wire [07:00] MemoryByte0_02 = MemoryBlock0[02];
wire [07:00] MemoryByte0_03 = MemoryBlock0[03];
wire [07:00] MemoryByte0_04 = MemoryBlock0[04];
wire [07:00] MemoryByte0_05 = MemoryBlock0[05];
wire [07:00] MemoryByte0_06 = MemoryBlock0[06];
wire [07:00] MemoryByte0_07 = MemoryBlock0[07];
wire [07:00] MemoryByte0_08 = MemoryBlock0[08];
wire [07:00] MemoryByte0_09 = MemoryBlock0[09];
wire [07:00] MemoryByte0_0A = MemoryBlock0[10];
wire [07:00] MemoryByte0_0B = MemoryBlock0[11];
wire [07:00] MemoryByte0_0C = MemoryBlock0[12];
wire [07:00] MemoryByte0_0D = MemoryBlock0[13];
wire [07:00] MemoryByte0_0E = MemoryBlock0[14];
wire [07:00] MemoryByte0_0F = MemoryBlock0[15];
wire [07:00] MemoryByte1_00 = MemoryBlock1[00];
wire [07:00] MemoryByte1_01 = MemoryBlock1[01];
wire [07:00] MemoryByte1_02 = MemoryBlock1[02];
wire [07:00] MemoryByte1_03 = MemoryBlock1[03];
wire [07:00] MemoryByte1_04 = MemoryBlock1[04];
wire [07:00] MemoryByte1_05 = MemoryBlock1[05];
wire [07:00] MemoryByte1_06 = MemoryBlock1[06];
wire [07:00] MemoryByte1_07 = MemoryBlock1[07];
wire [07:00] MemoryByte1_08 = MemoryBlock1[08];
wire [07:00] MemoryByte1_09 = MemoryBlock1[09];
wire [07:00] MemoryByte1_0A = MemoryBlock1[10];
wire [07:00] MemoryByte1_0B = MemoryBlock1[11];
wire [07:00] MemoryByte1_0C = MemoryBlock1[12];
wire [07:00] MemoryByte1_0D = MemoryBlock1[13];
wire [07:00] MemoryByte1_0E = MemoryBlock1[14];
wire [07:00] MemoryByte1_0F = MemoryBlock1[15];
// -------------------------------------------------------------------------------------------------------
// 2.02: Write Data Buffer
// -------------------------------------------------------------------------------------------------------
wire [07:00] WriteData_0 = WrDataByte[00];
wire [07:00] WriteData_1 = WrDataByte[01];
wire [07:00] WriteData_2 = WrDataByte[02];
wire [07:00] WriteData_3 = WrDataByte[03];
wire [07:00] WriteData_4 = WrDataByte[04];
wire [07:00] WriteData_5 = WrDataByte[05];
wire [07:00] WriteData_6 = WrDataByte[06];
wire [07:00] WriteData_7 = WrDataByte[07];
wire [07:00] WriteData_8 = WrDataByte[08];
wire [07:00] WriteData_9 = WrDataByte[09];
wire [07:00] WriteData_A = WrDataByte[10];
wire [07:00] WriteData_B = WrDataByte[11];
wire [07:00] WriteData_C = WrDataByte[12];
wire [07:00] WriteData_D = WrDataByte[13];
wire [07:00] WriteData_E = WrDataByte[14];
wire [07:00] WriteData_F = WrDataByte[15];
// *******************************************************************************************************
// ** TIMING CHECKS **
// *******************************************************************************************************
wire TimingCheckEnable = (RESET == 0) & (SDA_OE == 0);
specify
specparam
tHI = 600, // SCL pulse width - high
tLO = 1300, // SCL pulse width - low
tSU_STA = 600, // SCL to SDA setup time
tHD_STA = 600, // SCL to SDA hold time
tSU_DAT = 100, // SDA to SCL setup time
tSU_STO = 600, // SCL to SDA setup time
tBUF = 1300; // Bus free time
$width (posedge SCL, tHI);
$width (negedge SCL, tLO);
$width (posedge SDA &&& SCL, tBUF);
$setup (posedge SCL, negedge SDA &&& TimingCheckEnable, tSU_STA);
$setup (SDA, posedge SCL &&& TimingCheckEnable, tSU_DAT);
$setup (posedge SCL, posedge SDA &&& TimingCheckEnable, tSU_STO);
$hold (negedge SDA &&& TimingCheckEnable, negedge SCL, tHD_STA);
endspecify
endmodule
2、M24LC64仿真模型供大家使用
// *******************************************************************************************************
// ** **
// ** 24LC64.v - Microchip 24LC64 64K-BIT I2C SERIAL EEPROM (VCC = +2.5V TO +5.5V) **
// ** **
// *******************************************************************************************************
// ** **
// ** This information is distributed under license from Young Engineering. **
// ** COPYRIGHT (c) 2009 YOUNG ENGINEERING **
// ** ALL RIGHTS RESERVED **
// ** **
// ** **
// ** Young Engineering provides design expertise for the digital world **
// ** Started in 1990, Young Engineering offers products and services for your electronic design **
// ** project. We have the expertise in PCB, FPGA, ASIC, firmware, and software design. **
// ** From concept to prototype to production, we can help you. **
// ** **
// ** http://www.young-engineering.com/ **
// ** **
// *******************************************************************************************************
// ** This information is provided to you for your convenience and use with Microchip products only. **
// ** Microchip disclaims all liability arising from this information and its use. **
// ** **
// ** THIS INFORMATION IS PROVIDED "AS IS." MICROCHIP MAKES NO REPRESENTATION OR WARRANTIES OF **
// ** ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO **
// ** THE INFORMATION PROVIDED TO YOU, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, **
// ** PERFORMANCE, MERCHANTABILITY, NON-INFRINGEMENT, OR FITNESS FOR PURPOSE. **
// ** MICROCHIP IS NOT LIABLE, UNDER ANY CIRCUMSTANCES, FOR SPECIAL, INCIDENTAL OR CONSEQUENTIAL **
// ** DAMAGES, FOR ANY REASON WHATSOEVER. **
// ** **
// ** It is your responsibility to ensure that your application meets with your specifications. **
// ** **
// *******************************************************************************************************
// ** Revision : 1.4 **
// ** Modified Date : 02/04/2009 **
// ** Revision History: **
// ** **
// ** 10/01/2003: Initial design **
// ** 07/19/2004: Fixed the timing checks and the open-drain modeling for SDA. **
// ** 01/06/2006: Changed the legal information in the header **
// ** 12/04/2006: Corrected timing checks to reference proper clock edges **
// ** Added timing check for Tbuf (bus free time) **
// ** Reduced memory blocks to single, monolithic array **
// ** 02/04/2009: Added timing checks for tSU_WP and tHD_WP **
// ** **
// *******************************************************************************************************
// ** TABLE OF CONTENTS **
// *******************************************************************************************************
// **---------------------------------------------------------------------------------------------------**
// ** DECLARATIONS **
// **---------------------------------------------------------------------------------------------------**
// **---------------------------------------------------------------------------------------------------**
// ** INITIALIZATION **
// **---------------------------------------------------------------------------------------------------**
// **---------------------------------------------------------------------------------------------------**
// ** CORE LOGIC **
// **---------------------------------------------------------------------------------------------------**
// ** 1.01: START Bit Detection **
// ** 1.02: STOP Bit Detection **
// ** 1.03: Input Shift Register **
// ** 1.04: Input Bit Counter **
// ** 1.05: Control Byte Register **
// ** 1.06: Byte Address Register **
// ** 1.07: Write Data Buffer **
// ** 1.08: Acknowledge Generator **
// ** 1.09: Acknowledge Detect **
// ** 1.10: Write Cycle Timer **
// ** 1.11: Write Cycle Processor **
// ** 1.12: Read Data Multiplexor **
// ** 1.13: Read Data Processor **
// ** 1.14: SDA Data I/O Buffer **
// ** **
// **---------------------------------------------------------------------------------------------------**
// ** DEBUG LOGIC **
// **---------------------------------------------------------------------------------------------------**
// ** 2.01: Memory Data Bytes **
// ** 2.02: Write Data Buffer **
// ** **
// **---------------------------------------------------------------------------------------------------**
// ** TIMING CHECKS **
// **---------------------------------------------------------------------------------------------------**
// ** **
// *******************************************************************************************************
`timescale 1ns/10ps
module M24LC64 (A0, A1, A2, WP, SDA, SCL, RESET);
input A0; // chip select bit
input A1; // chip select bit
input A2; // chip select bit
input WP; // write protect pin
inout SDA; // serial data I/O
input SCL; // serial data clock
input RESET; // system reset
// *******************************************************************************************************
// ** DECLARATIONS **
// *******************************************************************************************************
reg SDA_DO; // serial data - output
reg SDA_OE; // serial data - output enable
wire SDA_DriveEnable; // serial data output enable
reg SDA_DriveEnableDlyd; // serial data output enable - delayed
wire [02:00] ChipAddress; // hardwired chip address
reg [03:00] BitCounter; // serial bit counter
reg START_Rcvd; // START bit received flag
reg STOP_Rcvd; // STOP bit received flag
reg CTRL_Rcvd; // control byte received flag
reg ADHI_Rcvd; // byte address hi received flag
reg ADLO_Rcvd; // byte address lo received flag
reg MACK_Rcvd; // master acknowledge received flag
reg WrCycle; // memory write cycle
reg RdCycle; // memory read cycle
reg [07:00] ShiftRegister; // input data shift register
reg [07:00] ControlByte; // control byte register
wire RdWrBit; // read/write control bit
reg [12:00] StartAddress; // memory access starting address
reg [04:00] PageAddress; // memory page address
reg [07:00] WrDataByte [0:31]; // memory write data buffer
wire [07:00] RdDataByte; // memory read data
reg [15:00] WrCounter; // write buffer counter
reg [04:00] WrPointer; // write buffer pointer
reg [12:00] RdPointer; // read address pointer
reg WriteActive; // memory write cycle active
reg [07:00] MemoryBlock [0:8191]; // EEPROM data memory array
integer LoopIndex; // iterative loop index
integer tAA; // timing parameter
integer tWC; // timing parameter
// *******************************************************************************************************
// ** INITIALIZATION **
// *******************************************************************************************************
//----------------------------
//------写数据间隔改动----------
initial tAA = 900; // SCL to SDA output delay
initial tWC = 500; // memory write cycle time
// initial tAA = 900; // SCL to SDA output delay
// initial tWC = 5000000; // memory write cycle time
initial begin
SDA_DO = 0;
SDA_OE = 0;
end
initial begin
START_Rcvd = 0;
STOP_Rcvd = 0;
CTRL_Rcvd = 0;
ADHI_Rcvd = 0;
ADLO_Rcvd = 0;
MACK_Rcvd = 0;
end
initial begin
BitCounter = 0;
ControlByte = 0;
end
initial begin
WrCycle = 0;
RdCycle = 0;
WriteActive = 0;
end
assign ChipAddress = {A2,A1,A0};
// *******************************************************************************************************
// ** CORE LOGIC **
// *******************************************************************************************************
// -------------------------------------------------------------------------------------------------------
// 1.01: START Bit Detection
// -------------------------------------------------------------------------------------------------------
always @(negedge SDA) begin
if (SCL == 1) begin
START_Rcvd <= 1;
STOP_Rcvd <= 0;
CTRL_Rcvd <= 0;
ADHI_Rcvd <= 0;
ADLO_Rcvd <= 0;
MACK_Rcvd <= 0;
WrCycle <= #1 0;
RdCycle <= #1 0;
BitCounter <= 0;
end
end
// -------------------------------------------------------------------------------------------------------
// 1.02: STOP Bit Detection
// -------------------------------------------------------------------------------------------------------
always @(posedge SDA) begin
if (SCL == 1) begin
START_Rcvd <= 0;
STOP_Rcvd <= 1;
CTRL_Rcvd <= 0;
ADHI_Rcvd <= 0;
ADLO_Rcvd <= 0;
MACK_Rcvd <= 0;
WrCycle <= #1 0;
RdCycle <= #1 0;
BitCounter <= 10;
end
end
// -------------------------------------------------------------------------------------------------------
// 1.03: Input Shift Register
// -------------------------------------------------------------------------------------------------------
always @(posedge SCL) begin
ShiftRegister[00] <= SDA;
ShiftRegister[01] <= ShiftRegister[00];
ShiftRegister[02] <= ShiftRegister[01];
ShiftRegister[03] <= ShiftRegister[02];
ShiftRegister[04] <= ShiftRegister[03];
ShiftRegister[05] <= ShiftRegister[04];
ShiftRegister[06] <= ShiftRegister[05];
ShiftRegister[07] <= ShiftRegister[06];
end
// -------------------------------------------------------------------------------------------------------
// 1.04: Input Bit Counter
// -------------------------------------------------------------------------------------------------------
always @(posedge SCL) begin
if (BitCounter < 10) BitCounter <= BitCounter + 1;
end
// -------------------------------------------------------------------------------------------------------
// 1.05: Control Byte Register
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (START_Rcvd & (BitCounter == 8)) begin
if (!WriteActive & (ShiftRegister[07:01] == {4'b1010,ChipAddress[02:00]})) begin
if (ShiftRegister[00] == 0) WrCycle <= 1;
if (ShiftRegister[00] == 1) RdCycle <= 1;
ControlByte <= ShiftRegister[07:00];
CTRL_Rcvd <= 1;
end
START_Rcvd <= 0;
end
end
assign RdWrBit = ControlByte[00];
// -------------------------------------------------------------------------------------------------------
// 1.06: Byte Address Register
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (CTRL_Rcvd & (BitCounter == 8)) begin
if (RdWrBit == 0) begin
StartAddress[12:08] <= ShiftRegister[04:00];
RdPointer[12:08] <= ShiftRegister[04:00];
ADHI_Rcvd <= 1;
end
WrCounter <= 0;
WrPointer <= 0;
CTRL_Rcvd <= 0;
end
end
always @(negedge SCL) begin
if (ADHI_Rcvd & (BitCounter == 8)) begin
if (RdWrBit == 0) begin
StartAddress[07:00] <= ShiftRegister[07:00];
RdPointer[07:00] <= ShiftRegister[07:00];
ADLO_Rcvd <= 1;
end
WrCounter <= 0;
WrPointer <= 0;
ADHI_Rcvd <= 0;
end
end
// -------------------------------------------------------------------------------------------------------
// 1.07: Write Data Buffer
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (ADLO_Rcvd & (BitCounter == 8)) begin
if (RdWrBit == 0) begin
WrDataByte[WrPointer] <= ShiftRegister[07:00];
WrCounter <= WrCounter + 1;
WrPointer <= WrPointer + 1;
end
end
end
// -------------------------------------------------------------------------------------------------------
// 1.08: Acknowledge Generator
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (!WriteActive) begin
if (BitCounter == 8) begin
if (WrCycle | (START_Rcvd & (ShiftRegister[07:01] == {4'b1010,ChipAddress[02:00]}))) begin
SDA_DO <= 0;
SDA_OE <= 1;
end
end
if (BitCounter == 9) begin
BitCounter <= 0;
if (!RdCycle) begin
SDA_DO <= 0;
SDA_OE <= 0;
end
end
end
end
// -------------------------------------------------------------------------------------------------------
// 1.09: Acknowledge Detect
// -------------------------------------------------------------------------------------------------------
always @(posedge SCL) begin
if (RdCycle & (BitCounter == 8)) begin
if ((SDA == 0) & (SDA_OE == 0)) MACK_Rcvd <= 1;
end
end
always @(negedge SCL) MACK_Rcvd <= 0;
// -------------------------------------------------------------------------------------------------------
// 1.10: Write Cycle Timer
// -------------------------------------------------------------------------------------------------------
always @(posedge STOP_Rcvd) begin
if (WrCycle & (WP == 0) & (WrCounter > 0)) begin
WriteActive = 1;
#(tWC);
WriteActive = 0;
end
end
always @(posedge STOP_Rcvd) begin
#(1.0);
STOP_Rcvd = 0;
end
// -------------------------------------------------------------------------------------------------------
// 1.11: Write Cycle Processor
// -------------------------------------------------------------------------------------------------------
always @(negedge WriteActive) begin
for (LoopIndex = 0; LoopIndex < WrCounter; LoopIndex = LoopIndex + 1) begin
PageAddress = StartAddress[04:00] + LoopIndex;
MemoryBlock[{StartAddress[12:05],PageAddress[04:00]}] = WrDataByte[LoopIndex[04:00]];
end
end
// -------------------------------------------------------------------------------------------------------
// 1.12: Read Data Multiplexor
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (BitCounter == 8) begin
if (WrCycle & ADLO_Rcvd) begin
RdPointer <= StartAddress + WrPointer + 1;
end
if (RdCycle) begin
RdPointer <= RdPointer + 1;
end
end
end
assign RdDataByte = MemoryBlock[RdPointer[12:00]];
// -------------------------------------------------------------------------------------------------------
// 1.13: Read Data Processor
// -------------------------------------------------------------------------------------------------------
always @(negedge SCL) begin
if (RdCycle) begin
if (BitCounter == 8) begin
SDA_DO <= 0;
SDA_OE <= 0;
end
else if (BitCounter == 9) begin
SDA_DO <= RdDataByte[07];
if (MACK_Rcvd) SDA_OE <= 1;
end
else begin
SDA_DO <= RdDataByte[7-BitCounter];
end
end
end
// -------------------------------------------------------------------------------------------------------
// 1.14: SDA Data I/O Buffer
// -------------------------------------------------------------------------------------------------------
bufif1 (SDA, 1'b0, SDA_DriveEnableDlyd);
assign SDA_DriveEnable = !SDA_DO & SDA_OE;
always @(SDA_DriveEnable) SDA_DriveEnableDlyd <= #(tAA) SDA_DriveEnable;
// *******************************************************************************************************
// ** DEBUG LOGIC **
// *******************************************************************************************************
// -------------------------------------------------------------------------------------------------------
// 2.01: Memory Data Bytes
// -------------------------------------------------------------------------------------------------------
wire [07:00] MemoryByte_000 = MemoryBlock[00];
wire [07:00] MemoryByte_001 = MemoryBlock[01];
wire [07:00] MemoryByte_002 = MemoryBlock[02];
wire [07:00] MemoryByte_003 = MemoryBlock[03];
wire [07:00] MemoryByte_004 = MemoryBlock[04];
wire [07:00] MemoryByte_005 = MemoryBlock[05];
wire [07:00] MemoryByte_006 = MemoryBlock[06];
wire [07:00] MemoryByte_007 = MemoryBlock[07];
wire [07:00] MemoryByte_008 = MemoryBlock[08];
wire [07:00] MemoryByte_009 = MemoryBlock[09];
wire [07:00] MemoryByte_00A = MemoryBlock[10];
wire [07:00] MemoryByte_00B = MemoryBlock[11];
wire [07:00] MemoryByte_00C = MemoryBlock[12];
wire [07:00] MemoryByte_00D = MemoryBlock[13];
wire [07:00] MemoryByte_00E = MemoryBlock[14];
wire [07:00] MemoryByte_00F = MemoryBlock[15];
// -------------------------------------------------------------------------------------------------------
// 2.02: Write Data Buffer
// -------------------------------------------------------------------------------------------------------
wire [07:00] WriteData_00 = WrDataByte[00];
wire [07:00] WriteData_01 = WrDataByte[01];
wire [07:00] WriteData_02 = WrDataByte[02];
wire [07:00] WriteData_03 = WrDataByte[03];
wire [07:00] WriteData_04 = WrDataByte[04];
wire [07:00] WriteData_05 = WrDataByte[05];
wire [07:00] WriteData_06 = WrDataByte[06];
wire [07:00] WriteData_07 = WrDataByte[07];
wire [07:00] WriteData_08 = WrDataByte[08];
wire [07:00] WriteData_09 = WrDataByte[09];
wire [07:00] WriteData_0A = WrDataByte[10];
wire [07:00] WriteData_0B = WrDataByte[11];
wire [07:00] WriteData_0C = WrDataByte[12];
wire [07:00] WriteData_0D = WrDataByte[13];
wire [07:00] WriteData_0E = WrDataByte[14];
wire [07:00] WriteData_0F = WrDataByte[15];
wire [07:00] WriteData_10 = WrDataByte[16];
wire [07:00] WriteData_11 = WrDataByte[17];
wire [07:00] WriteData_12 = WrDataByte[18];
wire [07:00] WriteData_13 = WrDataByte[19];
wire [07:00] WriteData_14 = WrDataByte[20];
wire [07:00] WriteData_15 = WrDataByte[21];
wire [07:00] WriteData_16 = WrDataByte[22];
wire [07:00] WriteData_17 = WrDataByte[23];
wire [07:00] WriteData_18 = WrDataByte[24];
wire [07:00] WriteData_19 = WrDataByte[25];
wire [07:00] WriteData_1A = WrDataByte[26];
wire [07:00] WriteData_1B = WrDataByte[27];
wire [07:00] WriteData_1C = WrDataByte[28];
wire [07:00] WriteData_1D = WrDataByte[29];
wire [07:00] WriteData_1E = WrDataByte[30];
wire [07:00] WriteData_1F = WrDataByte[31];
// *******************************************************************************************************
// ** TIMING CHECKS **
// *******************************************************************************************************
wire TimingCheckEnable = (RESET == 0) & (SDA_OE == 0);
wire StopTimingCheckEnable = TimingCheckEnable && SCL;
//--------------------------------
//-------仿真时时序约束需改动--------
//--------------------------------
specify
specparam
tHI = 600, // SCL pulse width - high
// tLO = 1300, // SCL pulse width - low
tLO = 600,
tSU_STA = 600, // SCL to SDA setup time
tHD_STA = 600, // SCL to SDA hold time
tSU_DAT = 100, // SDA to SCL setup time
tSU_STO = 600, // SCL to SDA setup time
tSU_WP = 600, // WP to SDA setup time
tHD_WP = 1300, // WP to SDA hold time
// tBUF = 1300; // Bus free time
tBUF = 600;
$width (posedge SCL, tHI);
$width (negedge SCL, tLO);
$width (posedge SDA &&& SCL, tBUF);
$setup (posedge SCL, negedge SDA &&& TimingCheckEnable, tSU_STA);
$setup (SDA, posedge SCL &&& TimingCheckEnable, tSU_DAT);
$setup (posedge SCL, posedge SDA &&& TimingCheckEnable, tSU_STO);
$setup (WP, posedge SDA &&& StopTimingCheckEnable, tSU_WP);
$hold (negedge SDA &&& TimingCheckEnable, negedge SCL, tHD_STA);
$hold (posedge SDA &&& StopTimingCheckEnable, WP, tHD_WP);
endspecify
endmodule
三、testbench文件
`timescale 1ns / 1ps
module i2c_bit_shift_tb;
reg Clk;
reg Rst_n;
reg [5:0] Cmd;
reg Go;
wire [7:0] Rx_DATA;
reg [7:0] Tx_DATA;
wire Trans_Done;
wire ack_o;
wire i2c_sclk;
wire i2c_sdat;
pullup PUP(i2c_sdat);
localparam
WR = 6'b000001, //写请求
STA = 6'b000010, //起始位请求
RD = 6'b000100, //读请求
STO = 6'b001000, //停止位请求
ACK = 6'b010000, //应答位请求
NACK = 6'b100000; //无应答请求
i2c_bit_shift DUT(
.Clk(Clk),
.Rst_n(Rst_n),
.Cmd(Cmd),
.Go(Go),
.Rx_DATA(Rx_DATA),
.Tx_DATA(Tx_DATA),
.Trans_Done(Trans_Done),
.ack_o(ack_o),
.i2c_sclk(i2c_sclk),
.i2c_sdat(i2c_sdat)
);
M24LC04B M24LC04B(
.A0(0),
.A1(0),
.A2(0),
.WP(0),
.SDA(i2c_sdat),
.SCL(i2c_sclk),
.RESET(~Rst_n)
);
always #10 Clk = ~Clk;
initial begin
Clk = 1;
Rst_n = 0;
Cmd = 6'b000000;
Go = 0;
Tx_DATA = 8'd0;
#2001;
Rst_n = 1;
#2000;
//写数据操作，往EEPROM器件的B1地址写数据DA
//第一次：起始位+EEPROM器件地址（7位）+写方向（1位）
Cmd = STA | WR;
Go = 1;
Tx_DATA = 8'hA0 | 8'd0;//写方向
@ (posedge Clk);
Go = 0;
@ (posedge Trans_Done);
#200;
//第二次：写8位EEPROM的寄存器地址
Cmd = WR;
Go = 1;
Tx_DATA = 8'hB1;//写地址B1
@ (posedge Clk);
Go = 0;
@ (posedge Trans_Done);
#200;
//第三次：写8位数据 + 停止位
Cmd = WR | STO;
Go = 1;
Tx_DATA = 8'hda;//写数据DA
@ (posedge Clk);
Go = 0;
@ (posedge Trans_Done);
#200;
#5000000; //仿真模型的两次操作时间间隔
//读数据操作，从EEPROM器件的B1地址读数据
//第一次：起始位+EEPROM器件地址（7位）+写方向（1位）
Cmd = STA | WR;
Go = 1;
Tx_DATA = 8'hA0 | 8'd0;//写方向
@ (posedge Clk);
Go = 0;
@ (posedge Trans_Done);
#200;
//第二次：写8位EEPROM的寄存器地址
Cmd = WR;
Go = 1;
Tx_DATA = 8'hB1;//写地址B1
@ (posedge Clk);
Go = 0;
@ (posedge Trans_Done);
#200;
//第三次：起始位+EEPROM器件地址（7位）+读方向（1位）
Cmd = STA | WR;
Go = 1;
Tx_DATA = 8'hA0 | 8'd1;//读方向
@ (posedge Clk);
Go = 0;
@ (posedge Trans_Done);
#200;
//第四次：读8位数据 + 停止位
Cmd = RD | STO;
Go = 1;
@ (posedge Clk);
Go = 0;
@ (posedge Trans_Done);
#200;
#2000;
$stop;
end
endmodule
`timescale 1ns / 1ps
//
// Company:
// Engineer:
//
// Create Date: 2019/10/23 23:32:08
// Design Name:
// Module Name: i2c_control_tb
// Project Name:
// Target Devices:
// Tool Versions:
// Description:
//
// Dependencies:
//
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
//
//
module i2c_control_tb;
reg Clk;
reg Rst_n;
reg wrreg_req;
reg rdreg_req;
reg [15:0]addr;
reg addr_mode;
reg [7:0]wrdata;
wire [7:0]rddata;
reg [7:0]device_id;
wire RW_Done;
wire ack;
wire i2c_sclk;
wire i2c_sdat;
pullup PUP(i2c_sdat);
i2c_control DUT(
.Clk (Clk ),
.Rst_n (Rst_n ),
.wrreg_req (wrreg_req),
.rdreg_req (rdreg_req),
.addr (addr ),
.addr_mode (addr_mode),
.wrdata (wrdata ),
.rddata (rddata ),
.device_id (device_id),
.RW_Done (RW_Done ),
.ack (ack ),
.i2c_sclk (i2c_sclk ),
.i2c_sdat (i2c_sdat )
);
M24LC04B M24LC04B(
.A0(0),
.A1(0),
.A2(0),
.WP(0),
.SDA(i2c_sdat),
.SCL(i2c_sclk),
.RESET(~Rst_n)
);
initial Clk = 1;
always #10 Clk = ~Clk;
initial begin
Rst_n = 0;
rdreg_req = 0;
wrreg_req = 0;
#2001;
Rst_n = 1;
#2000;
write_one_byte(8'hA0,8'h0A,8'hd1);
write_one_byte(8'hA0,8'h0B,8'hd2);
write_one_byte(8'hA0,8'h0C,8'hd3);
write_one_byte(8'hA0,8'h0F,8'hd4);
read_one_byte(8'hA0,8'h0A);
read_one_byte(8'hA0,8'h0B);
read_one_byte(8'hA0,8'h0C);
read_one_byte(8'hA0,8'h0F);
$stop;
end
task write_one_byte;
input [7:0]id;
input [7:0]mem_address;
input [7:0]data;
begin
addr = {8'd0,mem_address};
device_id = id;
addr_mode = 0;
wrdata = data;
wrreg_req = 1;
#20;
wrreg_req = 0;
@(posedge RW_Done);
#5000000;
end
endtask
task read_one_byte;
input [7:0]id;
input [7:0]mem_address;
begin
addr = {8'd0,mem_address};
device_id = id;
addr_mode = 0;
rdreg_req = 1;
#20;
rdreg_req = 0;
@(posedge RW_Done);
#5000000;
end
endtask
endmodule
四、完整工程下载
芯路恒的开源工程，需要的自提。附文档。
链接：https://pan.baidu.com/s/1wdAYkX4ricvnc7v8yUNgRQ?pwd=FBMZ
提取码：FBMZ
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