SPI 协议简介
SPI 即 Serial Periphera linterface 的缩写，顾名思义就是串行外围设备接口，主要用于与FLASH、实时时钟、AD 转换器等外设模块的通信，它是一种高速的全双工同步的通信总线。
SPI 设备分为主设备和从设备，SPI 通信必须由主设备发起，主设备通过片选引脚（CSn）来选择对应的从设备，通过时钟引脚（SCK）向从设备提供时钟，通过数据输出引脚（MOSI）引脚向从设备发送数据，通过数据输入引脚（MISO）引脚来读取从设备返回的数据，如下是 SPI 的总线拓扑图(分别是1个主设备对应1个从设备和1个主设备对应多个从设备)：
SPI 时序
通过 SPI 的时钟极性（CPOL）和相位（ CPHA）可以组合出4种工作模式，如下表所示是对应的4种工作模式：
- 模式0（CPOL = 0， CPHA = 0）
CPOL = 0：空闲时是低电平，第一个跳变沿是上升沿，第二个跳变沿是下降沿
CPHA = 0：数据在第一个跳变沿（上升沿）采样
- 模式1（CPOL = 0， CPHA = 1）
CPOL = 0：空闲时是低电平，第一个跳变沿是上升沿，第二个跳变沿是下降沿
CPHA = 1：数据在第二个跳变沿（下降沿）采样
- 模式2（CPOL = 1， CPHA = 0）
CPOL = 1：空闲时是高电平，第一个跳变沿是下降沿，第二个跳变沿是上升沿
CPHA = 0：数据在第一个跳变沿（下降沿）采样
- 模式3（CPOL = 1， CPHA = 1）
CPOL = 1：空闲时是高电平，第一个跳变沿是下降沿，第二个跳变沿是上升沿
CPHA = 1：数据在第二个跳变沿（上升沿）采样
FLASH 简介
实验使用的 FLASH 芯片型号为W25Q128，它是华邦公司推出的一款的 NOR FIash 芯片，其存储空间为128 Mbit，相当于16MB，支持 Standard SPI、Dual SPI 和 Quad SPI 三种 SPI 协议通信方式，最大传输数据速率可达104MHZ，如下是芯片的引脚示意图：
存储结构
整个存储阵列被分成被为 256 给我块，每个块又分为 16 个扇区，每个扇区由分为 16 个页，每页包含 256 个字节。
操作指令
FLASH 操作指令有很多，其中常用的有读ID指令（0x9F）、写使能指令（0x06）、扇区擦除指令（每次擦除4KB，0x20）、全擦除指令（0xC7）、读指令（0x03）、写指令（又叫页编程，0x02）、读状态寄存器1指令（0x05）。
FLASH 操作时序
- 读ID指令
在操作 FLASH 之前应读取其ID，校验 FLASH 型号，如下是读 ID 的时序：
- 写使能指令
在进行擦除、写入操作前需要先发送写使能指令，其时序如下：
- 扇区擦除指令
W25Q128在写数据时只能将1修改为0，所以在写入新数据之前必须要进行擦除操作，将FLASH中的存储单元全部设置为1，如下是扇区擦除时序：
- 全擦除指令
除了扇区擦除指令外，还有全擦除指令，其时序如下：
- 读指令
读取 FLASH 一次可以读取多个字节，其时序如下：
- 写指令
向 FLASH 写入数据时不能跨页（页大小256B），若需要写入多页或者写入数据跨页则需要分多次写入，如下是写入数据的时序：
- 读状态寄存器1指令
在进行擦除、写入操作后需要轮询状态寄存器0的bit0，以检查擦除或写入操作是否结束（全擦除指令耗时很长），如下是读状态寄存器的时序：
硬件设计
FLASH 芯片的硬件原理图较为简单，芯片本身就 8 个引脚，其原理图如下：
代码编写
代码一共分为3个模块，分别是 SPI 驱动模块、FLASH 驱动模块、FLASH 读写测试模块，其功能如下：
SPI 驱动模块；提供 SPI 总线收发数据的功能。
FLASH 驱动模块；基于 SPI 驱动模块实现 FLASH 的一些基本操作，如读 ID、写使能、写、擦除、读、读状态寄存器等。
FLASH 读写测试模块；利用 FLASH 驱动模块提供的 FLASH 基本操作进行 FLASH 读ID、擦除、写、读等测试，测试过程中状态 LED 常灭，测试出错状态 LED闪烁，测试完成状态 LED 常亮。
SPI 驱动模块
c
module spi_driver #(
parameter SPI_CS_MAX = 1, //片选数量
parameter SPI_BITS = 8, //SPI位宽
parameter SPI_CLK_PERIOD = 4, //SPI时钟周期，以系统时钟为参考，最小为4
parameter SPI_MODE = 0, //SPI模式
parameter ALMOST_DONE_ADVANCE = 0, //即将传输完成信号提前输出时间，小于SPI_CLK_PERIOD-1
parameter ALMOST_IDLE_ADVANCE = 0 //即将空闲信号提前输出时间，小于SPI_CLK_PERIOD-1
)
(
input sys_rst_n, //系统复位
input sys_clk, //系统时钟
input [SPI_BITS-1:0] tx_data, //需要发送的数据
input tr_start, //启动传输
output reg [SPI_BITS-1:0] rx_data, //接收到的数据
output reg tr_done, //传输完成
output reg almost_tr_done, //传输即将完成
output tr_idle, //SPI空闲
output reg almost_tr_idle, //SPI即将空闲
input [SPI_CS_MAX-1:0] sel_cs, //片选设置
output spi_clk, //SPI时钟
output spi_mosi, //SPI MOSI
input spi_miso, //SPI MISO
output [SPI_CS_MAX-1:0] spi_cs //SPI片选
);
//SPI时钟周期，只能是偶数分频
localparam CLK_PERIOD = (SPI_CLK_PERIOD / 2 * 2);
//spi传输忙标志
reg tr_busy;
//SPI时钟周期计数器，按SPI时钟周期进行计数
reg [15:0] clk_period_count;
//传输bit计数
reg [7:0] bit_cnt;
//发送移位寄存器
reg [SPI_BITS-1:0] tx_shift_reg;
//接收移位寄存器
reg [SPI_BITS-1:0] rx_shift_reg;
//空闲标志
assign tr_idle = ~tr_busy;
//启动SPI传输
always @(posedge sys_clk) begin
if(!sys_rst_n)
tr_busy <= 1'b0;
else if((tr_start == 1'b1) && (tr_busy == 1'b0))
tr_busy <= 1'b1;
else if((tr_busy == 1'b1) && (bit_cnt == (SPI_BITS - 1)) && (clk_period_count == (CLK_PERIOD - 1)))
tr_busy <= 1'b0;
end
//SPI即将空闲
always @(posedge sys_clk) begin
if(!sys_rst_n)
almost_tr_idle <= 1'b1;
else if((tr_start == 1'b1) && (almost_tr_idle == 1'b1))
almost_tr_idle <= 1'b0;
else if((almost_tr_idle == 1'b0) && (bit_cnt == (SPI_BITS - 1)) && (clk_period_count == (CLK_PERIOD - 1 - ALMOST_IDLE_ADVANCE)))
almost_tr_idle <= 1'b1;
end
//按SPI时钟周期进行计数
always @(posedge sys_clk) begin
if(!sys_rst_n)
clk_period_count <= 0;
else if(tr_busy == 1'b1)
if(clk_period_count < (CLK_PERIOD - 1))
clk_period_count <= clk_period_count + 1;
else
clk_period_count <= 0;
else
clk_period_count <= 0;
end
//进行传输计数
always @(posedge sys_clk) begin
if(!sys_rst_n)
bit_cnt <= 0;
else if(tr_busy == 1'b1) begin
if(clk_period_count == (CLK_PERIOD - 1)) begin
if(bit_cnt < (SPI_BITS - 1))
bit_cnt <= bit_cnt + 1;
end
end
else
bit_cnt <= 0;
end
//输出接收到的数据，接收完最后1bit时输出
always @(posedge sys_clk) begin
if(!sys_rst_n) begin
rx_data <= 0;
tr_done <= 0;
end
else if((tr_busy == 1'b1) && (bit_cnt == (SPI_BITS - 1)) && (clk_period_count == (CLK_PERIOD - 1))) begin
rx_data <= rx_shift_reg;
tr_done <= 1;
end
else
tr_done <= 0;
end
//输出传输完成预告
always @(posedge sys_clk) begin
if(!sys_rst_n)
almost_tr_done <= 0;
else if((tr_busy == 1'b1) && (bit_cnt == (SPI_BITS - 1)) && (clk_period_count == (CLK_PERIOD - 1 - ALMOST_DONE_ADVANCE)))
almost_tr_done <= 1;
else
almost_tr_done <= 0;
end
generate
if(SPI_MODE == 0) begin
//输出SPI时钟，模式0
//时钟默认为低电平，工作时前半段为低电平，后半段为高电平
assign spi_clk = ((tr_busy == 1'b1) && (clk_period_count > (CLK_PERIOD / 2 - 1))) ? 1'b1 : 1'b0;
end
else if(SPI_MODE == 1) begin
//输出SPI时钟，模式1
//时钟默认为低电平，工作时前半段为高电平，后半段为低电平
assign spi_clk = ((tr_busy == 1'b1) && (clk_period_count <= (CLK_PERIOD / 2 - 1))) ? 1'b1 : 1'b0;
end
else if(SPI_MODE == 2) begin
//输出SPI时钟，模式2
//时钟默认为高电平，工作时前半段为高电平，后半段为低电平
assign spi_clk = ((tr_busy == 1'b1) && (clk_period_count > (CLK_PERIOD / 2 - 1))) ? 1'b0 : 1'b1;
end
else begin
//输出SPI时钟，模式3
//时钟默认为高电平，工作时前半段为高电平，后半段为低电平
assign spi_clk = ((tr_busy == 1'b1) && (clk_period_count <= (CLK_PERIOD / 2 - 1))) ? 1'b0 : 1'b1;
end
endgenerate
//启动时锁定数据，随后进行发送数据移位操作
always @(posedge sys_clk) begin
if(!sys_rst_n)
tx_shift_reg <= (1 << SPI_BITS) - 1;
else if((tr_start == 1'b1) && (tr_busy == 1'b0))
tx_shift_reg <= tx_data;
else if((tr_busy == 1'b1) && (bit_cnt < (SPI_BITS - 1)) && (clk_period_count == (CLK_PERIOD - 1)))
tx_shift_reg <= {tx_shift_reg[6:0], tx_shift_reg[7]};
end
//输出SPI MOSI
assign spi_mosi = tx_shift_reg[7];
//采样SPI MOSI
//在时钟周期的3/4处采样
always @(posedge sys_clk) begin
if(!sys_rst_n)
rx_shift_reg <= 0;
else if(tr_busy == 1'b1) begin
if(clk_period_count == (CLK_PERIOD - CLK_PERIOD / 4 - 1))
rx_shift_reg = {rx_shift_reg[6:0], spi_miso};
end
else
rx_shift_reg <= 0;
end
//输出片选信号
assign spi_cs = sel_cs;
endmoduleFLASH 驱动模块
c
module flash_driver #(
parameter SPI_CLK_PERIOD = 4,
parameter SPI_CS_DELAY = 500,
parameter DATA_REQ_ADVANCE = 1
)
(
input sys_rst_n,
input sys_clk,
input flash_start,
input [7:0] flash_cmd,
input [24:0] flash_addr,
input [8:0] wr_data_len,
input [7:0] wr_data,
output wr_data_req,
input [8:0] rd_data_len,
output [7:0] rd_data,
output rd_data_flag,
output reg [23:0] flash_id,
output reg flash_id_flag,
output reg [7:0] flash_sr_reg,
output reg flash_sr_reg_flag,
output flash_idle,
output spi_clk,
output spi_mosi,
input spi_miso,
output spi_cs
);
//状态机的状态
localparam IDLE_STATE = 8'h01; //空闲状态
localparam RDID_STATE = 8'h02; //读FLASH ID状态
localparam WREN_STATE = 8'h04; //写使能状态
localparam SSE_STATE = 8'h08; //子扇区擦除状态
localparam BE_STATE = 8'h10; //全擦除
localparam READ_STATE = 8'h20; //读状态
localparam PP_STATE = 8'h40; //写状态(页编程)
localparam RDSR_STATE = 8'h80; //读状态寄存器状态
//指令集
localparam RDID_CMD = 8'h9f; //读ID指令
localparam WREN_CMD = 8'h06; //写使能指令
localparam SSE_CMD = 8'h20; //子扇区擦除指令
localparam BE_CMD = 8'hc7; //全擦除指令
localparam READ_CMD = 8'h0b; //读指令
localparam PP_CMD = 8'h02; //写指令(页编程)
localparam RDSR_CMD = 8'h05; //读状态寄存器指令
//传输计数
reg [15:0] tx_count;
reg [15:0] rx_count;
//当前状态
reg [7:0] current_state;
//下一刻的状态
reg [7:0] next_state;
//当前状态结束标志，切换到下一个状态
reg state_done;
//片选前延时
reg [16:0] cs_front_delay_count;
//片选后延时
reg [16:0] cs_back_delay_count;
//指令操作延时，部分命令发送完成后需要延时
reg [16:0] cmd_back_ddelay_count;
//SPI需要发送的数据
reg [7:0] spi_tx_data;
//启动SPI发送
reg spi_tr_start;
//SPI片选控制
reg spi_ctrl_cs;
//SPI接收到的数据
wire [7:0] spi_rx_data;
//SPI传输完成
wire spi_tr_done;
//SPI即将传输完成
wire spi_almost_tr_done;
//SPI空闲
wire spi_tr_idle;
//SPI即将空闲
wire spi_almost_tr_idle;
//状态跳转
always @(posedge sys_clk)begin
if(!sys_rst_n)
current_state <= IDLE_STATE;
else
current_state <= next_state;
end
//根据当前状态确定下一刻状态
always @(*)begin
case(current_state)
IDLE_STATE: begin
if((state_done == 1'b0) && (flash_start == 1'b1) && (flash_cmd == RDID_CMD))
next_state = RDID_STATE;
else if((state_done == 1'b0) && (flash_start == 1'b1) && (flash_cmd == WREN_CMD))
next_state = WREN_STATE;
else if((state_done == 1'b0) && (flash_start == 1'b1) && (flash_cmd == SSE_CMD))
next_state = SSE_STATE;
else if((state_done == 1'b0) && (flash_start == 1'b1) && (flash_cmd == BE_CMD))
next_state = BE_STATE;
else if((state_done == 1'b0) && (flash_start == 1'b1) && (flash_cmd == READ_CMD))
next_state = READ_STATE;
else if((state_done == 1'b0) && (flash_start == 1'b1) && (flash_cmd == PP_CMD))
next_state = PP_STATE;
else if((state_done == 1'b0) && (flash_start == 1'b1) && (flash_cmd == RDSR_CMD))
next_state = RDSR_STATE;
else
next_state = IDLE_STATE;
end
RDID_STATE: begin
if(state_done == 1'b1)
next_state = IDLE_STATE;
else
next_state = RDID_STATE;
end
WREN_STATE: begin
if(state_done == 1'b1)
next_state = IDLE_STATE;
else
next_state = WREN_STATE;
end
SSE_STATE: begin
if(state_done == 1'b1)
next_state = IDLE_STATE;
else
next_state = SSE_STATE;
end
BE_STATE: begin
if(state_done == 1'b1)
next_state = IDLE_STATE;
else
next_state = BE_STATE;
end
READ_STATE: begin
if(state_done == 1'b1)
next_state = IDLE_STATE;
else
next_state = READ_STATE;
end
PP_STATE: begin
if(state_done == 1'b1)
next_state = IDLE_STATE;
else
next_state = PP_STATE;
end
RDSR_STATE: begin
if(state_done == 1'b1)
next_state = IDLE_STATE;
else
next_state = RDSR_STATE;
end
default:
next_state = IDLE_STATE;
endcase
end
//空闲标志输出
assign flash_idle = ((current_state == IDLE_STATE) && (state_done == 1'b0)) ? 1'b1 : 1'b0;
//进行计数器计数，输出延时信号
always @(posedge sys_clk) begin
if(!sys_rst_n) begin
cs_front_delay_count <= 0;
cs_back_delay_count <= 0;
cmd_back_ddelay_count <= 0;
state_done <= 1'b0;
end
else begin
case(current_state)
IDLE_STATE: begin
cs_front_delay_count <= 0;
cs_back_delay_count <= 0;
cmd_back_ddelay_count <= 0;
state_done <= 1'b0;
end
RDID_STATE: begin
//片选拉低后延时计数
if(cs_front_delay_count < (SPI_CS_DELAY - 1))
cs_front_delay_count <= cs_front_delay_count + 1;
//片选拉高前延时计数
if(rx_count >= 4) begin
if(cs_back_delay_count < (SPI_CS_DELAY - 1))
cs_back_delay_count <= cs_back_delay_count + 1;
end
//指令操作延时
if(cs_back_delay_count >= (SPI_CS_DELAY - 1)) begin
if(cmd_back_ddelay_count < (500 - 1))
cmd_back_ddelay_count <= cmd_back_ddelay_count + 1;
end
//状态结束判断
if(cmd_back_ddelay_count >= (500 - 1))
state_done <= 1'b1;
end
WREN_STATE: begin
//片选拉低后延时计数
if(cs_front_delay_count < (SPI_CS_DELAY - 1))
cs_front_delay_count <= cs_front_delay_count + 1;
//片选拉高前延时计数
if(rx_count >= 1) begin
if(cs_back_delay_count < (SPI_CS_DELAY - 1))
cs_back_delay_count <= cs_back_delay_count + 1;
end
//指令操作延时
if(cs_back_delay_count >= (SPI_CS_DELAY - 1)) begin
if(cmd_back_ddelay_count < (500 - 1))
cmd_back_ddelay_count <= cmd_back_ddelay_count + 1;
end
//状态结束判断
if(cmd_back_ddelay_count >= (500 - 1))
state_done <= 1'b1;
end
SSE_STATE: begin
//片选拉低后延时计数
if(cs_front_delay_count < (SPI_CS_DELAY - 1))
cs_front_delay_count <= cs_front_delay_count + 1;
//片选拉高前延时计数
if(rx_count >= 4) begin
if(cs_back_delay_count < (SPI_CS_DELAY - 1))
cs_back_delay_count <= cs_back_delay_count + 1;
end
//指令操作延时
if(cs_back_delay_count >= (SPI_CS_DELAY - 1)) begin
if(cmd_back_ddelay_count < (500 - 1))
cmd_back_ddelay_count <= cmd_back_ddelay_count + 1;
end
//状态结束判断
if(cmd_back_ddelay_count >= (500 - 1))
state_done <= 1'b1;
end
BE_STATE: begin
//片选拉低后延时计数
if(cs_front_delay_count < (SPI_CS_DELAY - 1))
cs_front_delay_count <= cs_front_delay_count + 1;
//片选拉高前延时计数
if(rx_count >= 1) begin
if(cs_back_delay_count < (SPI_CS_DELAY - 1))
cs_back_delay_count <= cs_back_delay_count + 1;
end
//指令操作延时
if(cs_back_delay_count >= (SPI_CS_DELAY - 1)) begin
if(cmd_back_ddelay_count < (500 - 1))
cmd_back_ddelay_count <= cmd_back_ddelay_count + 1;
end
//状态结束判断
if(cmd_back_ddelay_count >= (500 - 1))
state_done <= 1'b1;
end
READ_STATE: begin
//片选拉低后延时计数
if(cs_front_delay_count < (SPI_CS_DELAY - 1))
cs_front_delay_count <= cs_front_delay_count + 1;
//片选拉高前延时计数
if(rx_count >= (4 + rd_data_len)) begin
if(cs_back_delay_count < (SPI_CS_DELAY - 1))
cs_back_delay_count <= cs_back_delay_count + 1;
end
//指令操作延时
if(cs_back_delay_count >= (SPI_CS_DELAY - 1)) begin
if(cmd_back_ddelay_count < (500 - 1))
cmd_back_ddelay_count <= cmd_back_ddelay_count + 1;
end
//状态结束判断
if(cmd_back_ddelay_count >= (500 - 1))
state_done <= 1'b1;
end
PP_STATE: begin
//片选拉低后延时计数
if(cs_front_delay_count < (SPI_CS_DELAY - 1))
cs_front_delay_count <= cs_front_delay_count + 1;
//片选拉高前延时计数
if(rx_count >= (4 + wr_data_len)) begin
if(cs_back_delay_count < (SPI_CS_DELAY - 1))
cs_back_delay_count <= cs_back_delay_count + 1;
end
//指令操作延时
if(cs_back_delay_count >= (SPI_CS_DELAY - 1)) begin
if(cmd_back_ddelay_count < (500 - 1))
cmd_back_ddelay_count <= cmd_back_ddelay_count + 1;
end
//状态结束判断
if(cmd_back_ddelay_count >= (500 - 1))
state_done <= 1'b1;
end
RDSR_STATE: begin
//片选拉低后延时计数
if(cs_front_delay_count < (SPI_CS_DELAY - 1))
cs_front_delay_count <= cs_front_delay_count + 1;
//片选拉高前延时计数
if(rx_count >= 2) begin
if(cs_back_delay_count < (SPI_CS_DELAY - 1))
cs_back_delay_count <= cs_back_delay_count + 1;
end
//指令操作延时
if(cs_back_delay_count >= (SPI_CS_DELAY - 1)) begin
if(cmd_back_ddelay_count < (500 - 1))
cmd_back_ddelay_count <= cmd_back_ddelay_count + 1;
end
//状态结束判断
if(cmd_back_ddelay_count >= (500 - 1))
state_done <= 1'b1;
end
default: begin
cs_front_delay_count <= 0;
cs_back_delay_count <= 0;
cmd_back_ddelay_count <= 0;
state_done <= 1'b0;
end
endcase
end
end
//控制SPI传输
always @(posedge sys_clk)begin
if(!sys_rst_n) begin
spi_ctrl_cs <= 1'b1;
spi_tx_data <= 8'b0;
spi_tr_start <= 1'b0;
tx_count <= 16'b0;
end
else begin
case(current_state)
IDLE_STATE: begin
spi_ctrl_cs <= 1'b1;
spi_tx_data <= 8'b0;
spi_tr_start <= 1'b0;
tx_count <= 16'b0;
end
RDID_STATE: begin
//控制片选
if(cs_back_delay_count >= (SPI_CS_DELAY - 1))
spi_ctrl_cs <= 1'b1;
else
spi_ctrl_cs <= 1'b0;
//控制传输
if(cs_front_delay_count >= (SPI_CS_DELAY - 1)) begin
if((spi_almost_tr_idle == 1'b1) && (spi_tr_start == 1'b0)) begin
//启动spi传输
if(tx_count == 0) begin
spi_tx_data <= 8'h9f;
spi_tr_start <= 1'b1;
end
else if(tx_count < 4) begin
spi_tx_data <= 8'hFF;
spi_tr_start <= 1'b1;
end
//发送计数
if(tx_count < 4)
tx_count <= tx_count + 16'b1;
end
else if(spi_almost_tr_idle == 1'b0)
spi_tr_start <= 1'b0;
end
else
spi_tr_start <= 1'b0;
end
WREN_STATE: begin
//控制片选
if(cs_back_delay_count >= (SPI_CS_DELAY - 1))
spi_ctrl_cs <= 1'b1;
else
spi_ctrl_cs <= 1'b0;
//控制传输
if(cs_front_delay_count >= (SPI_CS_DELAY - 1)) begin
if((spi_almost_tr_idle == 1'b1) && (spi_tr_start == 1'b0)) begin
//启动spi传输
if(tx_count == 0) begin
spi_tx_data <= 8'h06;
spi_tr_start <= 1'b1;
end
//发送计数
if(tx_count < 1)
tx_count <= tx_count + 16'b1;
end
else if(spi_almost_tr_idle == 1'b0)
spi_tr_start <= 1'b0;
end
else
spi_tr_start <= 1'b0;
end
SSE_STATE: begin
//控制片选
if(cs_back_delay_count >= (SPI_CS_DELAY - 1))
spi_ctrl_cs <= 1'b1;
else
spi_ctrl_cs <= 1'b0;
//控制传输
if(cs_front_delay_count >= (SPI_CS_DELAY - 1)) begin
if((spi_almost_tr_idle == 1'b1) && (spi_tr_start == 1'b0)) begin
//启动spi传输
if(tx_count == 0) begin
spi_tx_data <= 8'h20;
spi_tr_start <= 1'b1;
end
else if(tx_count == 1) begin
spi_tx_data <= flash_addr[23:16];
spi_tr_start <= 1'b1;
end
else if(tx_count == 2) begin
spi_tx_data <= flash_addr[15:8];
spi_tr_start <= 1'b1;
end
else if(tx_count == 3) begin
spi_tx_data <= flash_addr[7:0];
spi_tr_start <= 1'b1;
end
//发送计数
if(tx_count < 4)
tx_count <= tx_count + 16'b1;
end
else if(spi_almost_tr_idle == 1'b0)
spi_tr_start <= 1'b0;
end
else
spi_tr_start <= 1'b0;
end
BE_STATE: begin
//控制片选
if(cs_back_delay_count >= (SPI_CS_DELAY - 1))
spi_ctrl_cs <= 1'b1;
else
spi_ctrl_cs <= 1'b0;
//控制传输
if(cs_front_delay_count >= (SPI_CS_DELAY - 1)) begin
if((spi_almost_tr_idle == 1'b1) && (spi_tr_start == 1'b0)) begin
//启动spi传输
if(tx_count == 0) begin
spi_tx_data <= 8'hc7;
spi_tr_start <= 1'b1;
end
//发送计数
if(tx_count < 1)
tx_count <= tx_count + 16'b1;
end
else if(spi_almost_tr_idle == 1'b0)
spi_tr_start <= 1'b0;
end
else
spi_tr_start <= 1'b0;
end
READ_STATE: begin
//控制片选
if(cs_back_delay_count >= (SPI_CS_DELAY - 1))
spi_ctrl_cs <= 1'b1;
else
spi_ctrl_cs <= 1'b0;
//控制传输
if(cs_front_delay_count >= (SPI_CS_DELAY - 1)) begin
if((spi_almost_tr_idle == 1'b1) && (spi_tr_start == 1'b0)) begin
//启动spi传输
if(tx_count == 0) begin
spi_tx_data <= 8'h03;
spi_tr_start <= 1'b1;
end
else if(tx_count == 1) begin
spi_tx_data <= flash_addr[23:16];
spi_tr_start <= 1'b1;
end
else if(tx_count == 2) begin
spi_tx_data <= flash_addr[15:8];
spi_tr_start <= 1'b1;
end
else if(tx_count == 3) begin
spi_tx_data <= flash_addr[7:0];
spi_tr_start <= 1'b1;
end
else if(tx_count < (4 + rd_data_len)) begin
spi_tx_data <= 8'hFF;
spi_tr_start <= 1'b1;
end
//发送计数
if(tx_count < (4 + rd_data_len))
tx_count <= tx_count + 16'b1;
end
else if(spi_almost_tr_idle == 1'b0)
spi_tr_start <= 1'b0;
end
else
spi_tr_start <= 1'b0;
end
PP_STATE: begin
//控制片选
if(cs_back_delay_count >= (SPI_CS_DELAY - 1))
spi_ctrl_cs <= 1'b1;
else
spi_ctrl_cs <= 1'b0;
//控制传输
if(cs_front_delay_count >= (SPI_CS_DELAY - 1)) begin
if((spi_almost_tr_idle == 1'b1) && (spi_tr_start == 1'b0)) begin
//启动spi传输
if(tx_count == 0) begin
spi_tx_data <= 8'h02;
spi_tr_start <= 1'b1;
end
else if(tx_count == 1) begin
spi_tx_data <= flash_addr[23:16];
spi_tr_start <= 1'b1;
end
else if(tx_count == 2) begin
spi_tx_data <= flash_addr[15:8];
spi_tr_start <= 1'b1;
end
else if(tx_count == 3) begin
spi_tx_data <= flash_addr[7:0];
spi_tr_start <= 1'b1;
end
else if(tx_count < (4 + wr_data_len)) begin
spi_tx_data <= wr_data;
spi_tr_start <= 1'b1;
end
//发送计数
if(tx_count < (4 + wr_data_len))
tx_count <= tx_count + 16'b1;
end
else if(spi_almost_tr_idle == 1'b0)
spi_tr_start <= 1'b0;
end
end
RDSR_STATE: begin
//控制片选
if(cs_back_delay_count >= (SPI_CS_DELAY - 1))
spi_ctrl_cs <= 1'b1;
else
spi_ctrl_cs <= 1'b0;
//控制传输
if(cs_front_delay_count >= (SPI_CS_DELAY - 1)) begin
if((spi_almost_tr_idle == 1'b1) && (spi_tr_start == 1'b0)) begin
//启动spi传输
if(tx_count == 0) begin
spi_tx_data <= 8'h05;
spi_tr_start <= 1'b1;
end
else if(tx_count < 2) begin
spi_tx_data <= 8'hFF;
spi_tr_start <= 1'b1;
end
//发送计数
if(tx_count < 2)
tx_count <= tx_count + 16'b1;
end
else if(spi_almost_tr_idle == 1'b0)
spi_tr_start <= 1'b0;
end
else
spi_tr_start <= 1'b0;
end
default: begin
spi_ctrl_cs <= 1'b1;
spi_tx_data <= 8'b0;
spi_tr_start <= 1'b0;
end
endcase
end
end
//处理读取ID和状态寄存器
always @(posedge sys_clk)begin
if(!sys_rst_n) begin
flash_id <= 24'b0;
flash_id_flag <= 1'b0;
flash_sr_reg <= 8'b0;
flash_sr_reg_flag <= 1'b0;
end
else begin
case(current_state)
RDID_STATE: begin
if(spi_tr_done == 1'b1) begin
if(rx_count == 1)
flash_id[23:16] <= spi_rx_data;
else if(rx_count == 2)
flash_id[15:8] <= spi_rx_data;
else if(rx_count == 3)
flash_id[7:0] <= spi_rx_data;
if(rx_count == 3)
flash_id_flag <= 1'b1;
else
flash_id_flag <= 1'b0;
end
else
flash_id_flag <= 1'b0;
end
RDSR_STATE: begin
if(spi_tr_done == 1'b1) begin
if(rx_count == 1)
flash_sr_reg <= spi_rx_data;
if(rx_count == 1)
flash_sr_reg_flag <= 1'b1;
else
flash_sr_reg_flag <= 1'b0;
end
else
flash_sr_reg_flag <= 1'b0;
end
default: begin
flash_id_flag <= 1'b0;
flash_sr_reg_flag <= 1'b0;
end
endcase
end
end
//SPI控制器接收计数
always @(posedge sys_clk)begin
if(!sys_rst_n)
rx_count <= 0;
else if((current_state != IDLE_STATE) && (spi_tr_done == 1'b1))
rx_count <= rx_count + 1;
else if(current_state == IDLE_STATE)
rx_count <= 0;
end
//flash数据输出
assign rd_data = ((current_state == READ_STATE) &&(rx_count >= 4)) ? spi_rx_data : 0'b0;
assign rd_data_flag = ((current_state == READ_STATE) &&(rx_count >= 4)) ? spi_tr_done : 0'b0;
//数据请求输出
assign wr_data_req = ((current_state == PP_STATE) &&(tx_count >= 4) && (tx_count < (4 + wr_data_len))) ? spi_almost_tr_done : 0'b0;
spi_driver #(
.SPI_CS_MAX(1),
.SPI_BITS(8),
.SPI_CLK_PERIOD(4),
.SPI_MODE(0),
//因为将外部数据转发到spi_driver需要一个时钟，所以这里加1个时钟周期
.ALMOST_DONE_ADVANCE(DATA_REQ_ADVANCE + 1),
//此模块准备数据需要一个时钟周期，所以为1
.ALMOST_IDLE_ADVANCE(1)
)
spi_driver_inst0(
.sys_rst_n(sys_rst_n),
.sys_clk(sys_clk),
.tx_data(spi_tx_data),
.tr_start(spi_tr_start),
.rx_data(spi_rx_data),
.tr_done(spi_tr_done),
.almost_tr_done(spi_almost_tr_done),
.tr_idle(spi_tr_idle),
.almost_tr_idle(spi_almost_tr_idle),
.sel_cs(spi_ctrl_cs),
.spi_clk(spi_clk),
.spi_mosi(spi_mosi),
.spi_miso(spi_miso),
.spi_cs(spi_cs)
);
endmoduleFLASH 读写测试模块
c
module spi_flash_rw_test #(
parameter ALARM_LED_PERIOD = 25'd25_000_000
)
(
input sys_rst_n,
input sys_clk,
output spi_mosi,
input spi_miso,
output spi_sclk,
output spi_cs,
output reg alarm_led
);
//flash指令集
localparam RDID_CMD = 8'h9f; //读ID指令
localparam WREN_CMD = 8'h06; //写使能指令
localparam SSE_CMD = 8'h20; //子扇区擦除指令
localparam BE_CMD = 8'hc7; //全擦除指令
localparam READ_CMD = 8'h0b; //读指令
localparam PP_CMD = 8'h02; //写指令(页编程)
localparam RDSR_CMD = 8'h05; //读状态寄存器指令
//状态机的状态
localparam IDLE_STATE = 16'h0001; //空闲状态
localparam RDID_STATE = 16'h0002; //读FLASH ID状态
localparam BE_WREN_STATE = 16'h0004; //全擦除前写使能状态
localparam BE_STATE = 16'h0008; //全擦除状态
localparam BE_WAIT_STATE = 16'h0010; //全擦除后等待flash空闲状态
localparam PP_WREN_STATE = 16'h0020; //页编程前写使能状态
localparam PP_STATE = 16'h0040; //写状态(页编程)
localparam PP_WAIT_STATE = 16'h0080; //页编程后等待flash空闲状态
localparam READ1_STATE = 16'h0100; //第一次读状态，验证写入数据是否成功
localparam SSE_WREN_STATE = 16'h0200; //子扇区擦除前写使能状态
localparam SSE_STATE = 16'h0400; //子扇区擦除状态
localparam SSE_WAIT_STATE = 16'h0800; //子扇区擦除后等待flash空闲状态
localparam READ2_STATE = 16'h1000; //第二次读状态，验证擦除是否成功
//错误指示
reg error_flag;
//警示LED闪烁计数器
reg [31:0] led_count;
//flash擦除或写入忙标志
reg flash_ew_busy;
//写入计数
reg [8:0] write_count;
//读取计数
reg [8:0] read_count;
//当前状态
reg [15:0] current_state;
//下一刻的状态
reg [15:0] next_state;
//对应状态结束标志，应切换到下一个状态，一个bit对应一个状态
reg [15:0] state_done;
//状态启动标志
reg [15:0] state_start;
//flash操作开始信号
reg flash_start;
//flash操作命令
reg [7:0] flash_cmd;
//flash操作地址
reg [24:0] flash_addr;
//flash写入长度
reg [8:0] wr_data_len;
//写入flash的数据，需要在收到wr_data_req后更新
reg [7:0] wr_data;
//flash写入数据请求
wire wr_data_req;
//flash读长度
reg [8:0]rd_data_len;
//flash中读取到的数据
wire [7:0] rd_data;
//flash读取数据有效标志
wire rd_data_flag;
//flash ID
wire [23:0] flash_id;
//flash ID有效标志
wire flash_id_flag;
//flash 状态寄存器0
wire [7:0] flash_sr_reg;
//flash 状态寄存器0有效标志
wire flash_sr_reg_flag;
//flash空闲标志
wire flash_driver_idle;
//根据错误标志控制led闪烁或常亮
//操作未完成熄灭
//操作完成常亮
//发生错误时闪烁
always @(posedge sys_clk) begin
if(!sys_rst_n) begin
alarm_led <= 1'b0;
led_count <= 32'b0;
end
else if(error_flag == 1'b1) begin
if(led_count >= (ALARM_LED_PERIOD - 1)) begin
alarm_led <= ~alarm_led;
led_count <= 32'b0;
end
else
led_count <= led_count + 32'b1;
end
else if((current_state == IDLE_STATE) && (state_done != 16'h0)) begin
alarm_led <= 1'b1;
led_count <= 32'b0;
end
else begin
alarm_led <= 1'b0;
led_count <= 32'b0;
end
end
//状态跳转
always @(posedge sys_clk)begin
if(!sys_rst_n)
current_state <= IDLE_STATE;
else
current_state <= next_state;
end
//根据当前状态确定下一刻状态
always @(*)begin
case(current_state)
IDLE_STATE: begin
if((state_done == 16'h0) && (error_flag == 1'b0))
next_state = RDID_STATE;
else
next_state = IDLE_STATE;
end
RDID_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & RDID_STATE)
next_state = BE_WREN_STATE;
else
next_state = RDID_STATE;
end
BE_WREN_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & BE_WREN_STATE)
next_state = BE_STATE;
else
next_state = BE_WREN_STATE;
end
BE_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & BE_STATE)
next_state = BE_WAIT_STATE;
else
next_state = BE_STATE;
end
BE_WAIT_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & BE_WAIT_STATE)
next_state = PP_WREN_STATE;
else
next_state = BE_WAIT_STATE;
end
PP_WREN_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & PP_WREN_STATE)
next_state = PP_STATE;
else
next_state = PP_WREN_STATE;
end
PP_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & PP_STATE)
next_state = PP_WAIT_STATE;
else
next_state = PP_STATE;
end
PP_WAIT_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & PP_WAIT_STATE)
next_state = READ1_STATE;
else
next_state = PP_WAIT_STATE;
end
READ1_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & READ1_STATE)
next_state = SSE_WREN_STATE;
else
next_state = READ1_STATE;
end
SSE_WREN_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & SSE_WREN_STATE)
next_state = SSE_STATE;
else
next_state = SSE_WREN_STATE;
end
SSE_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & SSE_STATE)
next_state = SSE_WAIT_STATE;
else
next_state = SSE_STATE;
end
SSE_WAIT_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & SSE_WAIT_STATE)
next_state = READ2_STATE;
else
next_state = SSE_WAIT_STATE;
end
READ2_STATE: begin
if(error_flag == 1'b1)
next_state = IDLE_STATE;
else if(state_done & READ2_STATE)
next_state = IDLE_STATE;
else
next_state = READ2_STATE;
end
default:
next_state = IDLE_STATE;
endcase
end
//控制flash擦除、读写等
always @(posedge sys_clk)begin
if(!sys_rst_n) begin
flash_start <= 1'b0;
flash_cmd <= 8'h0;
flash_addr <= 24'h0;
wr_data_len <= 9'h0;
rd_data_len <= 9'h0;
state_done <= 16'h0;
state_start <= 16'h0;
end
else begin
case(current_state)
RDID_STATE: begin
//启动读ID操作
if((flash_driver_idle == 1'b1) && (!(state_start & RDID_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= RDID_CMD;
state_start <= state_start | RDID_STATE;
end
//读ID操作完成
if((flash_driver_idle == 1'b1) && (state_start & RDID_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & RDID_STATE))
state_done <= state_done | RDID_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
BE_WREN_STATE: begin
//启动写使能操作
if((flash_driver_idle == 1'b1) && (!(state_start & BE_WREN_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= WREN_CMD;
state_start <= state_start | BE_WREN_STATE;
end
//写使能操作完成
if((flash_driver_idle == 1'b1) && (state_start & BE_WREN_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & BE_WREN_STATE))
state_done <= state_done | BE_WREN_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
BE_STATE: begin
//启动全擦除操作
if((flash_driver_idle == 1'b1) && (!(state_start & BE_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= BE_CMD;
state_start <= state_start | BE_STATE;
end
//全擦除操作完成
if((flash_driver_idle == 1'b1) && (state_start & BE_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & BE_STATE))
state_done <= state_done | BE_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
BE_WAIT_STATE: begin
//启动读状态寄存器操作
if((flash_driver_idle == 1'b1) && (!(state_start & BE_WAIT_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= RDSR_CMD;
state_start <= state_start | BE_WAIT_STATE;
end
//读状态寄存器操作完成
if((flash_driver_idle == 1'b1) && (state_start & BE_WAIT_STATE) && (flash_start == 1'b0)) begin
//检查擦除是否结束，若未结束则再次轮询状态寄存器
if(flash_ew_busy == 1'b1)
state_start <= state_start & ~BE_WAIT_STATE;
else if(!(state_done & BE_WAIT_STATE))
state_done <= state_done | BE_WAIT_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
PP_WREN_STATE: begin
//启动写使能操作
if((flash_driver_idle == 1'b1) && (!(state_start & PP_WREN_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= WREN_CMD;
state_start <= state_start | PP_WREN_STATE;
end
//写使能操作完成
if((flash_driver_idle == 1'b1) && (state_start & PP_WREN_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & PP_WREN_STATE))
state_done <= state_done | PP_WREN_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
PP_STATE: begin
//启动写flash操作
if((flash_driver_idle == 1'b1) && (!(state_start & PP_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= PP_CMD;
flash_addr <= 24'h1000;
wr_data_len <= 9'd256;
state_start <= state_start | PP_STATE;
end
//写操作完成
if((flash_driver_idle == 1'b1) && (state_start & PP_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & PP_STATE))
state_done <= state_done | PP_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
PP_WAIT_STATE: begin
//启动读状态寄存器操作
if((flash_driver_idle == 1'b1) && (!(state_start & PP_WAIT_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= RDSR_CMD;
state_start <= state_start | PP_WAIT_STATE;
end
//读状态寄存器操作完成
if((flash_driver_idle == 1'b1) && (state_start & PP_WAIT_STATE) && (flash_start == 1'b0)) begin
//检查擦除是否结束，若未结束则再次轮询状态寄存器
if(flash_ew_busy == 1'b1)
state_start <= state_start & ~PP_WAIT_STATE;
else if(!(state_done & PP_WAIT_STATE))
state_done <= state_done | PP_WAIT_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
READ1_STATE: begin
//启动读flash操作
if((flash_driver_idle == 1'b1) && (!(state_start & READ1_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= READ_CMD;
flash_addr <= 24'h1000;
rd_data_len <= 9'd256;
state_start <= state_start | READ1_STATE;
end
//读操作完成
if((flash_driver_idle == 1'b1) && (state_start & READ1_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & READ1_STATE))
state_done <= state_done | READ1_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
SSE_WREN_STATE: begin
//启动写使能操作
if((flash_driver_idle == 1'b1) && (!(state_start & SSE_WREN_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= WREN_CMD;
state_start <= state_start | SSE_WREN_STATE;
end
//写使能操作完成
if((flash_driver_idle == 1'b1) && (state_start & SSE_WREN_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & SSE_WREN_STATE))
state_done <= state_done | SSE_WREN_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
SSE_STATE: begin
//启动子扇区擦除操作
if((flash_driver_idle == 1'b1) && (!(state_start & SSE_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= SSE_CMD;
flash_addr <= 24'h1000;
state_start <= state_start | SSE_STATE;
end
//子扇区擦除操作完成
if((flash_driver_idle == 1'b1) && (state_start & SSE_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & SSE_STATE))
state_done <= state_done | SSE_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
SSE_WAIT_STATE: begin
//启动读状态寄存器操作
if((flash_driver_idle == 1'b1) && (!(state_start & SSE_WAIT_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= RDSR_CMD;
state_start <= state_start | SSE_WAIT_STATE;
end
//读状态寄存器操作完成
if((flash_driver_idle == 1'b1) && (state_start & SSE_WAIT_STATE) && (flash_start == 1'b0)) begin
//检查擦除是否结束，若未结束则再次轮询状态寄存器
if(flash_ew_busy == 1'b1)
state_start <= state_start & ~SSE_WAIT_STATE;
else if(!(state_done & SSE_WAIT_STATE))
state_done <= state_done | SSE_WAIT_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
READ2_STATE: begin
//启动读flash操作
if((flash_driver_idle == 1'b1) && (!(state_start & READ2_STATE)) && (flash_start == 1'b0)) begin
flash_start <= 1'b1;
flash_cmd <= READ_CMD;
flash_addr <= 24'h1000;
rd_data_len <= 9'd256;
state_start <= state_start | READ2_STATE;
end
//读操作完成
if((flash_driver_idle == 1'b1) && (state_start & READ2_STATE) && (flash_start == 1'b0)) begin
if(!(state_done & READ2_STATE))
state_done <= state_done | READ2_STATE;
end
//flash操作已经启动，复位启动标志
if((flash_driver_idle == 1'b0) && (flash_start == 1'b1))
flash_start <= 1'b0;
end
default: begin
flash_start <= 1'b0;
flash_cmd <= 8'h0;
flash_addr <= 24'h0;
end
endcase
end
end
//处理flash driver返回的数据，包括ID、读取数据、状态寄存器
always @(posedge sys_clk)begin
if(!sys_rst_n) begin
error_flag <= 1'b0;
flash_ew_busy <= 1'h0;
read_count <= 9'h0;
end
else begin
case(current_state)
RDID_STATE: begin
//检查ID是否正确
if(flash_id_flag == 1'b1) begin
if(flash_id != 24'hef4018)
error_flag <= 1'b1;
end
end
BE_WAIT_STATE: begin
//检查擦除是否完成
if(flash_sr_reg_flag == 1'b1)
flash_ew_busy <= flash_sr_reg[0];
end
PP_WAIT_STATE: begin
//检查写是否完成
if(flash_sr_reg_flag == 1'b1)
flash_ew_busy <= flash_sr_reg[0];
end
READ1_STATE: begin
if(rd_data_flag == 1'b1) begin
//检查接收的数据
if(rd_data != read_count[7:0])
error_flag <= 1'b1;
//接收计数
read_count <= read_count + 9'h1;
end
end
SSE_WAIT_STATE: begin
//检查子扇区擦除是否完成
if(flash_sr_reg_flag == 1'b1)
flash_ew_busy <= flash_sr_reg[0];
end
READ2_STATE: begin
if(rd_data_flag == 1'b1) begin
//检查接收的数据
if(rd_data != 8'hff)
error_flag <= 1'b1;
end
end
default: begin
read_count <= 9'h0;
end
endcase
end
end
//生成写入的数据
always @(posedge sys_clk)begin
if(!sys_rst_n) begin
wr_data <= 8'h0;
write_count <= 9'h0;
end
else if(current_state == PP_STATE) begin
if(wr_data_req == 1'b1) begin
//生成写入数据
wr_data <= write_count[7:0];
//写入计数
write_count <= write_count + 9'h1;
end
end
else begin
wr_data <= 0;
write_count <= 0;
end
end
flash_driver #(
.SPI_CLK_PERIOD(4),
.SPI_CS_DELAY(500),
.DATA_REQ_ADVANCE(1)
)
flash_driver_inst0(
.sys_rst_n(sys_rst_n),
.sys_clk(sys_clk),
.flash_start(flash_start),
.flash_cmd(flash_cmd),
.flash_addr(flash_addr),
.wr_data_len(wr_data_len),
.wr_data(wr_data),
.wr_data_req(wr_data_req),
.rd_data_len(rd_data_len),
.rd_data(rd_data),
.rd_data_flag(rd_data_flag),
.flash_id(flash_id),
.flash_id_flag(flash_id_flag),
.flash_sr_reg(flash_sr_reg),
.flash_sr_reg_flag(flash_sr_reg_flag),
.flash_idle(flash_driver_idle),
.spi_clk(spi_sclk),
.spi_mosi(spi_mosi),
.spi_miso(spi_miso),
.spi_cs(spi_cs)
);
endmodule仿真激励
c
`timescale 1ns / 1ps
module tb_spi_flash_rw_test( );
reg sys_rst_n;
reg sys_clk;
wire spi_mosi;
reg spi_miso;
wire spi_clk;
wire spi_cs;
wire alarm_led;
reg [7:0] miso_data;
reg signed [7:0] loop_cnt1;
reg [16:0] loop_cnt2;
initial begin
sys_clk = 1'b0;
sys_rst_n = 1'b0;
#200
sys_rst_n = 1'b1;
end
//产生MISO
initial begin
spi_miso = 1'b1;
//模拟读flash ID
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'hef;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'h40;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'h18;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟写使能
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟全擦除
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟全擦除忙
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'h01;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟全擦除空闲
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'h00;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟写使能
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟写
wait(spi_cs == 1'b0);
for(loop_cnt2 = 0; loop_cnt2 < 4; loop_cnt2 = loop_cnt2 + 1) begin
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
end
for(loop_cnt2 = 0; loop_cnt2 < 256; loop_cnt2 = loop_cnt2 + 1) begin
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟写忙
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'h01;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟写空闲
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'h00;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟读
wait(spi_cs == 1'b0);
for(loop_cnt2 = 0; loop_cnt2 < 5; loop_cnt2 = loop_cnt2 + 1) begin
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
end
for(loop_cnt2 = 0; loop_cnt2 < 256; loop_cnt2 = loop_cnt2 + 1) begin
miso_data = loop_cnt2[7:0];
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟写使能
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟子扇区擦除
wait(spi_cs == 1'b0);
for(loop_cnt2 = 0; loop_cnt2 < 4; loop_cnt2 = loop_cnt2 + 1) begin
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟子扇区擦除忙
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'h01;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟子扇区擦除空闲
wait(spi_cs == 1'b0);
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
miso_data = 8'h00;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
//模拟读
wait(spi_cs == 1'b0);
for(loop_cnt2 = 0; loop_cnt2 < 5; loop_cnt2 = loop_cnt2 + 1) begin
miso_data = 8'h0;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
end
for(loop_cnt2 = 0; loop_cnt2 < 256; loop_cnt2 = loop_cnt2 + 1) begin
miso_data = 8'hff;
for(loop_cnt1 = 7; loop_cnt1 >= 0; loop_cnt1 = loop_cnt1 - 1) begin
wait((spi_clk == 1'b0) && (spi_cs == 1'b0));
spi_miso = miso_data[loop_cnt1];
wait((spi_clk == 1'b1) && (spi_cs == 1'b0));
end
end
wait(spi_cs == 1'b1);
spi_miso = 1'b1;
end
//产生时钟
always #10 sys_clk = ~sys_clk;
spi_flash_rw_test #(
.ALARM_LED_PERIOD(25'd250)
)
tb_spi_flash_rw_test_inst0(
.sys_rst_n(sys_rst_n),
.sys_clk(sys_clk),
.spi_mosi(spi_mosi),
.spi_miso(spi_miso),
.spi_sclk(spi_clk),
.spi_cs(spi_cs),
.alarm_led(alarm_led)
);
endmodule引脚约束
c
create_clock -period 20.000 -name sys_clk -waveform {0.000 10.000} [get_ports sys_clk]
set_property IOSTANDARD LVCMOS15 [get_ports sys_clk]
set_property PACKAGE_PIN R4 [get_ports sys_clk]
set_property IOSTANDARD LVCMOS15 [get_ports sys_rst_n]
set_property PACKAGE_PIN U7 [get_ports sys_rst_n]
set_property IOSTANDARD LVCMOS15 [get_ports alarm_led]
set_property PACKAGE_PIN V9 [get_ports alarm_led]
set_property IOSTANDARD LVCMOS33 [get_ports spi_cs]
set_property PACKAGE_PIN N14 [get_ports spi_cs]
set_property IOSTANDARD LVCMOS33 [get_ports spi_miso]
set_property PACKAGE_PIN N13 [get_ports spi_miso]
set_property IOSTANDARD LVCMOS33 [get_ports spi_mosi]
set_property PACKAGE_PIN R14 [get_ports spi_mosi]
set_property IOSTANDARD LVCMOS33 [get_ports spi_sclk]
set_property PACKAGE_PIN P14 [get_ports spi_sclk]