SDRAM全称“Synchronous Dynamic Random Access Memory”,译为“同步动态随机存取内存”或“同步动态随机存储器”,是动态随机存储器(Dynamic Random Access Memory,DRAM)家族的一份子。
`timescale 1ns/1nsmodule sdram_init
(input wire sys_clk , //系统时钟,频率100MHzinput wire sys_rst_n , //复位信号,低电平有效output reg [3:0] init_cmd , //初始化阶段写入sdram的指令,{cs_n,ras_n,cas_n,we_n}output reg [1:0] init_ba , //初始化阶段Bank地址output reg [12:0] init_addr , //初始化阶段地址数据,辅助预充电操作//和配置模式寄存器操作,A12-A0,共13位output wire init_end //初始化结束信号
);// parameter define
parameter T_POWER = 15'd20_000 ; //上电后等待时钟数(200us)
//SDRAM初始化用到的控制信号命令
parameter P_CHARGE = 4'b0010 , //预充电指令AUTO_REF = 4'b0001 , //自动刷新指令NOP = 4'b0111 , //空操作指令M_REG_SET = 4'b0000 ; //模式寄存器设置指令
//SDRAM初始化过程各个状态
parameter INIT_IDLE = 3'b000 , //初始状态INIT_PRE = 3'b001 , //预充电状态INIT_TRP = 3'b011 , //预充电等待 tRPINIT_AR = 3'b010 , //自动刷新INIT_TRF = 3'b100 , //自动刷新等待 tRCINIT_MRS = 3'b101 , //模式寄存器设置INIT_TMRD = 3'b111 , //模式寄存器设置等待 tMRDINIT_END = 3'b110 ; //初始化完成
parameter TRP_CLK = 3'd2 , //预充电等待周期,20nsTRC_CLK = 3'd7 , //自动刷新等待,70nsTMRD_CLK = 3'd3 ; //模式寄存器设置等待周期,30ns// wire define
wire wait_end ; //上电后200us等待结束标志
wire trp_end ; //预充电等待结束标志
wire trc_end ; //自动刷新等待结束标志
wire tmrd_end ; //模式寄存器设置等待结束标志// reg define
reg [14:0] cnt_200us ; //SDRAM上电后200us稳定期计数器
reg [2:0] init_state ; //SDRAM初始化状态
reg [2:0] cnt_clk ; //时钟周期计数,记录初始化各状态等待周期数
reg cnt_clk_rst ; //时钟周期计数复位标志
reg [3:0] cnt_init_aref ; //初始化过程自动刷新次数计数器//cnt_200us:SDRAM上电后200us稳定期计数器
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_200us <= 15'd0;else if(cnt_200us == T_POWER)cnt_200us <= T_POWER;elsecnt_200us <= cnt_200us + 1'b1;//wait_end:上电后200us等待结束标志
assign wait_end = (cnt_200us == (T_POWER - 1'b1)) ? 1'b1 : 1'b0;//init_end:SDRAM初始化完毕信号
assign init_end = (init_state == INIT_END) ? 1'b1 : 1'b0;//cnt_clk:时钟周期计数,记录初始化各状态等待时间
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_clk <= 3'd0;else if(cnt_clk_rst == 1'b1)cnt_clk <= 3'd0;elsecnt_clk <= cnt_clk + 1'b1;//cnt_init_aref:初始化过程自动刷新次数计数器
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_init_aref <= 4'd0;else if(init_state == INIT_IDLE)cnt_init_aref <= 4'd0;else if(init_state == INIT_AR)cnt_init_aref <= cnt_init_aref + 1'b1;elsecnt_init_aref <= cnt_init_aref;//trp_end,trc_end,tmrd_end:等待结束标志
assign trp_end = ((init_state == INIT_TRP ) && (cnt_clk == TRP_CLK )) ? 1'b1 : 1'b0;
assign trc_end = ((init_state == INIT_TRF ) && (cnt_clk == TRC_CLK )) ? 1'b1 : 1'b0;
assign tmrd_end = ((init_state == INIT_TMRD) && (cnt_clk == TMRD_CLK)) ? 1'b1 : 1'b0;//SDRAM的初始化状态机
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)init_state <= INIT_IDLE;elsecase(init_state)INIT_IDLE: //系统上电后,在初始状态等待200us跳转到预充电状态if(wait_end == 1'b1)init_state <= INIT_PRE;elseinit_state <= init_state;INIT_PRE: //预充电状态,直接跳转到预充电等待状态init_state <= INIT_TRP;INIT_TRP: //预充电等待状态,等待结束,跳转到自动刷新状态if(trp_end == 1'b1)init_state <= INIT_AR;elseinit_state <= init_state;INIT_AR : //自动刷新状态,直接跳转到自动刷新等待状态init_state <= INIT_TRF;INIT_TRF: //自动刷新等待状态,等待结束,自动跳转到模式寄存器设置状态if(trc_end == 1'b1)if(cnt_init_aref == 4'd8)init_state <= INIT_MRS;elseinit_state <= INIT_AR;elseinit_state <= init_state;INIT_MRS: //模式寄存器设置状态,直接跳转到模式寄存器设置等待状态init_state <= INIT_TMRD;INIT_TMRD: //模式寄存器设置等待状态,等待结束,跳到初始化完成状态if(tmrd_end == 1'b1)init_state <= INIT_END;elseinit_state <= init_state;INIT_END: //初始化完成状态,保持此状态init_state <= INIT_END;default: init_state <= INIT_IDLE;endcase//cnt_clk_rst:时钟周期计数复位标志
always@(*)begincase (init_state)INIT_IDLE: cnt_clk_rst <= 1'b1; //时钟周期计数复位信号,高有效,时钟周期计数清零INIT_TRP: cnt_clk_rst <= (trp_end == 1'b1) ? 1'b1 : 1'b0;//等待结束标志有效,计数器清零INIT_TRF: cnt_clk_rst <= (trc_end == 1'b1) ? 1'b1 : 1'b0; //等待结束标志有效,计数器清零INIT_TMRD: cnt_clk_rst <= (tmrd_end == 1'b1) ? 1'b1 : 1'b0;//等待结束标志有效,计数器清零INIT_END: cnt_clk_rst <= 1'b1; //初始化完成,计数器清零default: cnt_clk_rst <= 1'b0;endcaseend//SDRAM操作指令控制
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)begininit_cmd <= NOP;init_ba <= 2'b11;init_addr <= 13'h1fff;endelsecase(init_state)INIT_IDLE,INIT_TRP,INIT_TRF,INIT_TMRD: //执行空操作指令begininit_cmd <= NOP;init_ba <= 2'b11;init_addr <= 13'h1fff;endINIT_PRE: //预充电指令begininit_cmd <= P_CHARGE;init_ba <= 2'b11;init_addr <= 13'h1fff;end INIT_AR: //自动刷新指令begininit_cmd <= AUTO_REF;init_ba <= 2'b11;init_addr <= 13'h1fff;endINIT_MRS: //模式寄存器设置指令begininit_cmd <= M_REG_SET;init_ba <= 2'b00;init_addr <={ //地址辅助配置模式寄存器,参数不同,配置的模式不同3'b000, //A12-A10:预留1'b0, //A9=0:读写方式,0:突发读&突发写,1:突发读&单写2'b00, //{A8,A7}=00:标准模式,默认3'b011, //{A6,A5,A4}=011:CAS潜伏期,010:2,011:3,其他:保留1'b0, //A3=0:突发传输方式,0:顺序,1:隔行3'b111 //{A2,A1,A0}=111:突发长度,000:单字节,001:2字节//010:4字节,011:8字节,111:整页,其他:保留};end INIT_END: //SDRAM初始化完成begininit_cmd <= NOP;init_ba <= 2'b11;init_addr <= 13'h1fff;enddefault:begininit_cmd <= NOP;init_ba <= 2'b11;init_addr <= 13'h1fff;end endcaseendmodule
`timescale 1ns/1nsmodule sdram_a_ref
(input wire sys_clk , //系统时钟,频率100MHzinput wire sys_rst_n , //复位信号,低电平有效input wire init_end , //初始化结束信号input wire aref_en , //自动刷新使能output reg aref_req , //自动刷新请求output reg [3:0] aref_cmd , //自动刷新阶段写入sdram的指令,{cs_n,ras_n,cas_n,we_n}output reg [1:0] aref_ba , //自动刷新阶段Bank地址output reg [12:0] aref_addr , //地址数据,辅助预充电操作,A12-A0,13位地址output wire aref_end //自动刷新结束标志
);//parameter define
parameter CNT_REF_MAX = 10'd749 ; //自动刷新等待时钟数(7.5us)
parameter TRP_CLK = 3'd2 , //预充电等待周期TRC_CLK = 3'd7 ; //自动刷新等待周期
parameter P_CHARGE = 4'b0010 , //预充电指令A_REF = 4'b0001 , //自动刷新指令NOP = 4'b0111 ; //空操作指令
parameter AREF_IDLE = 3'b000 , //初始状态,等待自动刷新使能AREF_PCHA = 3'b001 , //预充电状态AREF_TRP = 3'b011 , //预充电等待 tRPAUTO_REF = 3'b010 , //自动刷新状态AREF_TRF = 3'b100 , //自动刷新等待 tRCAREF_END = 3'b101 ; //自动刷新结束//wire define
wire trp_end ; //预充电等待结束标志
wire trc_end ; //自动刷新等待结束标志
wire aref_ack ; //自动刷新应答信号//reg define
reg [9:0] cnt_aref ; //自动刷新计数器
reg [2:0] aref_state ; //SDRAM自动刷新状态
reg [2:0] cnt_clk ; //时钟周期计数,记录自刷新阶段各状态等待时间
reg cnt_clk_rst ; //时钟周期计数复位标志
reg [1:0] cnt_aref_aref ; //自动刷新次数计数器//cnt_ref:刷新计数器
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_aref <= 10'd0;else if(cnt_aref >= CNT_REF_MAX)cnt_aref <= 10'd0;else if(init_end == 1'b1)cnt_aref <= cnt_aref + 1'b1;else cnt_aref <= cnt_aref;//aref_req:自动刷新请求
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)aref_req <= 1'b0;else if(cnt_aref == CNT_REF_MAX - 1'b1)aref_req <= 1'b1;else if(aref_ack == 1'b1)aref_req <= 1'b0;//aref_ack:自动刷新应答信号
assign aref_ack = (aref_state == AREF_PCHA ) ? 1'b1 : 1'b0;
//aref_end:自动刷新结束标志
assign aref_end = (aref_state == AREF_END ) ? 1'b1 : 1'b0;//cnt_clk:时钟周期计数,记录初始化各状态等待时间
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_clk <= 3'd0;else if(cnt_clk_rst == 1'b1)cnt_clk <= 3'd0;elsecnt_clk <= cnt_clk + 1'b1;//trp_end,trc_end,tmrd_end:等待结束标志
assign trp_end = ((aref_state == AREF_TRP) && (cnt_clk == TRP_CLK )) ? 1'b1 : 1'b0;
assign trc_end = ((aref_state == AREF_TRF) && (cnt_clk == TRC_CLK )) ? 1'b1 : 1'b0;//cnt_aref_aref:初始化过程自动刷新次数计数器
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_aref_aref <= 2'd0;else if(aref_state == AREF_IDLE)cnt_aref_aref <= 2'd0;else if(aref_state == AUTO_REF)cnt_aref_aref <= cnt_aref_aref + 1'b1;elsecnt_aref_aref <= cnt_aref_aref;//SDRAM自动刷新状态机
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)aref_state <= AREF_IDLE;elsecase(aref_state)AREF_IDLE:if((aref_en == 1'b1) && (init_end == 1'b1))aref_state <= AREF_PCHA;elsearef_state <= aref_state;AREF_PCHA:aref_state <= AREF_TRP;AREF_TRP:if(trp_end == 1'b1)aref_state <= AUTO_REF;elsearef_state <= aref_state;AUTO_REF:aref_state <= AREF_TRF;AREF_TRF:if(trc_end == 1'b1)if(cnt_aref_aref == 2'd2)aref_state <= AREF_END;elsearef_state <= AUTO_REF;elsearef_state <= aref_state;AREF_END:aref_state <= AREF_IDLE;default:aref_state <= AREF_IDLE;endcase//cnt_clk_rst:时钟周期计数复位标志
always@(*)begincase (aref_state)AREF_IDLE: cnt_clk_rst <= 1'b1; //时钟周期计数器清零AREF_TRP: cnt_clk_rst <= (trp_end == 1'b1) ? 1'b1 : 1'b0;//等待结束标志有效,计数器清零AREF_TRF: cnt_clk_rst <= (trc_end == 1'b1) ? 1'b1 : 1'b0;//等待结束标志有效,计数器清零AREF_END: cnt_clk_rst <= 1'b1;default: cnt_clk_rst <= 1'b0;endcaseend//SDRAM操作指令控制
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)beginaref_cmd <= NOP;aref_ba <= 2'b11;aref_addr <= 13'h1fff;endelsecase(aref_state)AREF_IDLE,AREF_TRP,AREF_TRF: //执行空操作指令beginaref_cmd <= NOP;aref_ba <= 2'b11;aref_addr <= 13'h1fff;endAREF_PCHA: //预充电指令beginaref_cmd <= P_CHARGE;aref_ba <= 2'b11;aref_addr <= 13'h1fff;end AUTO_REF: //自动刷新指令beginaref_cmd <= A_REF;aref_ba <= 2'b11;aref_addr <= 13'h1fff;endAREF_END: //一次自动刷新完成beginaref_cmd <= NOP;aref_ba <= 2'b11;aref_addr <= 13'h1fff;end default:beginaref_cmd <= NOP;aref_ba <= 2'b11;aref_addr <= 13'h1fff;end endcaseendmodule
`timescale 1ns/1nsmodule sdram_write
(input wire sys_clk , //系统时钟,频率100MHzinput wire sys_rst_n , //复位信号,低电平有效input wire init_end , //初始化结束信号input wire wr_en , //写使能input wire [23:0] wr_addr , //写SDRAM地址input wire [15:0] wr_data , //待写入SDRAM的数据(写FIFO传入)input wire [9:0] wr_burst_len , //写突发SDRAM字节数output wire wr_ack , //写SDRAM响应信号output wire wr_end , //一次突发写结束output reg [3:0] write_cmd , //写数据阶段写入sdram的指令,{cs_n,ras_n,cas_n,we_n}output reg [1:0] write_ba , //写数据阶段Bank地址output reg [12:0] write_addr , //地址数据,辅助预充电操作,行、列地址,A12-A0,13位地址output reg wr_sdram_en , //数据总线输出使能output wire [15:0] wr_sdram_data //写入SDRAM的数据
);//parameter define
parameter TRCD_CLK = 10'd2 , //激活周期TRP_CLK = 10'd2 ; //预充电周期
parameter WR_IDLE = 4'b0000 , //初始状态WR_ACTIVE = 4'b0001 , //激活WR_TRCD = 4'b0011 , //激活等待WR_WRITE = 4'b0010 , //写操作WR_DATA = 4'b0100 , //写数据WR_PRE = 4'b0101 , //预充电WR_TRP = 4'b0111 , //预充电等待WR_END = 4'b0110 ; //一次突发写结束
parameter NOP = 4'b0111 , //空操作指令ACTIVE = 4'b0011 , //激活指令WRITE = 4'b0100 , //数据写指令B_STOP = 4'b0110 , //突发停止指令P_CHARGE = 4'b0010 ; //预充电指令//wire define
wire trcd_end ; //激活等待周期结束
wire twrite_end ; //突发写结束
wire trp_end ; //预充电有效周期结束//reg define
reg [3:0] write_state ; //SDRAM写状态
reg [9:0] cnt_clk ; //时钟周期计数,记录写数据阶段各状态等待时间
reg cnt_clk_rst ; //时钟周期计数复位标志//wr_end:一次突发写结束
assign wr_end = (write_state == WR_END) ? 1'b1 : 1'b0;//wr_ack:写SDRAM响应信号
assign wr_ack = ( write_state == WR_WRITE) || ((write_state == WR_DATA) && (cnt_clk <= wr_burst_len - 2'd2));//cnt_clk:时钟周期计数,记录初始化各状态等待时间
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_clk <= 10'd0;else if(cnt_clk_rst == 1'b1)cnt_clk <= 10'd0;elsecnt_clk <= cnt_clk + 1'b1;//trcd_end,twrite_end,trp_end:等待结束标志
assign trcd_end = ((write_state == WR_TRCD)&&(cnt_clk == TRCD_CLK )) ? 1'b1 : 1'b0; //激活周期结束
assign twrite_end = ((write_state == WR_DATA)&&(cnt_clk == wr_burst_len - 1)) ? 1'b1 : 1'b0; //突发写结束
assign trp_end = ((write_state == WR_TRP )&&(cnt_clk == TRP_CLK )) ? 1'b1 : 1'b0; //预充电等待周期结束//write_state:SDRAM的工作状态机
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)write_state <= WR_IDLE;elsecase(write_state)WR_IDLE:if((wr_en ==1'b1) && (init_end == 1'b1))write_state <= WR_ACTIVE;elsewrite_state <= write_state;WR_ACTIVE:write_state <= WR_TRCD;WR_TRCD:if(trcd_end == 1'b1)write_state <= WR_WRITE;elsewrite_state <= write_state;WR_WRITE:write_state <= WR_DATA;WR_DATA:if(twrite_end == 1'b1)write_state <= WR_PRE;elsewrite_state <= write_state;WR_PRE:write_state <= WR_TRP;WR_TRP:if(trp_end == 1'b1)write_state <= WR_END;elsewrite_state <= write_state;WR_END:write_state <= WR_IDLE;default:write_state <= WR_IDLE;endcase//计数器控制逻辑
always@(*)begincase(write_state)WR_IDLE: cnt_clk_rst <= 1'b1;WR_TRCD: cnt_clk_rst <= (trcd_end == 1'b1) ? 1'b1 : 1'b0;WR_WRITE: cnt_clk_rst <= 1'b1;WR_DATA: cnt_clk_rst <= (twrite_end == 1'b1) ? 1'b1 : 1'b0;WR_TRP: cnt_clk_rst <= (trp_end == 1'b1) ? 1'b1 : 1'b0;WR_END: cnt_clk_rst <= 1'b1;default: cnt_clk_rst <= 1'b0;endcaseend//SDRAM操作指令控制
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)beginwrite_cmd <= NOP;write_ba <= 2'b11;write_addr <= 13'h1fff;endelsecase(write_state)WR_IDLE,WR_TRCD,WR_TRP:beginwrite_cmd <= NOP;write_ba <= 2'b11;write_addr <= 13'h1fff;endWR_ACTIVE: //激活指令beginwrite_cmd <= ACTIVE;write_ba <= wr_addr[23:22];write_addr <= wr_addr[21:9];endWR_WRITE: //写操作指令beginwrite_cmd <= WRITE;write_ba <= wr_addr[23:22];write_addr <= {4'b0000,wr_addr[8:0]};end WR_DATA: //突发传输终止指令beginif(twrite_end == 1'b1)write_cmd <= B_STOP;elsebeginwrite_cmd <= NOP;write_ba <= 2'b11;write_addr <= 13'h1fff;endendWR_PRE: //预充电指令beginwrite_cmd <= P_CHARGE;write_ba <= wr_addr[23:22];write_addr <= 13'h0400;endWR_END:beginwrite_cmd <= NOP;write_ba <= 2'b11;write_addr <= 13'h1fff;enddefault:beginwrite_cmd <= NOP;write_ba <= 2'b11;write_addr <= 13'h1fff;endendcase//wr_sdram_en:数据总线输出使能
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)wr_sdram_en <= 1'b0;elsewr_sdram_en <= wr_ack;//wr_sdram_data:写入SDRAM的数据
assign wr_sdram_data = (wr_sdram_en == 1'b1) ? wr_data : 16'd0;endmodule
`timescale 1ns/1nsmodule sdram_read
(input wire sys_clk , //系统时钟,频率100MHzinput wire sys_rst_n , //复位信号,低电平有效input wire init_end , //初始化结束信号input wire rd_en , //读使能input wire [23:0] rd_addr , //读SDRAM地址input wire [15:0] rd_data , //自SDRAM中读出的数据input wire [9:0] rd_burst_len , //读突发SDRAM字节数output wire rd_ack , //读SDRAM响应信号output wire rd_end , //一次突发读结束output reg [3:0] read_cmd , //读数据阶段写入sdram的指令,{cs_n,ras_n,cas_n,we_n}output reg [1:0] read_ba , //读数据阶段Bank地址output reg [12:0] read_addr , //地址数据,辅助预充电操作,行、列地址,A12-A0,13位地址output wire [15:0] rd_sdram_data //SDRAM读出的数据
);//parameter define
parameter TRCD_CLK = 10'd2 , //激活等待周期TCL_CLK = 10'd3 , //潜伏期TRP_CLK = 10'd2 ; //预充电等待周期
parameter RD_IDLE = 4'b0000 , //空闲RD_ACTIVE = 4'b0001 , //激活RD_TRCD = 4'b0011 , //激活等待RD_READ = 4'b0010 , //读操作RD_CL = 4'b0100 , //潜伏期RD_DATA = 4'b0101 , //读数据RD_PRE = 4'b0111 , //预充电RD_TRP = 4'b0110 , //预充电等待RD_END = 4'b1100 ; //一次突发读结束
parameter NOP = 4'b0111 , //空操作指令ACTIVE = 4'b0011 , //激活指令READ = 4'b0101 , //数据读指令B_STOP = 4'b0110 , //突发停止指令P_CHARGE = 4'b0010 ; //预充电指令//wire define
wire trcd_end ; //激活等待周期结束
wire trp_end ; //预充电等待周期结束
wire tcl_end ; //潜伏期结束标志
wire tread_end ; //突发读结束
wire rdburst_end ; //读突发终止//reg define
reg [3:0] read_state ; //SDRAM写状态
reg [9:0] cnt_clk ; //时钟周期计数,记录初始化各状态等待时间
reg cnt_clk_rst ; //时钟周期计数复位标志
reg [15:0] rd_data_reg ;//rd_data_reg
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rd_data_reg <= 16'd0;elserd_data_reg <= rd_data;//rd_end:一次突发读结束
assign rd_end = (read_state == RD_END) ? 1'b1 : 1'b0;
//rd_ack:读SDRAM响应信号
assign rd_ack = (read_state == RD_DATA) && (cnt_clk >= 10'd1) && (cnt_clk < (rd_burst_len + 2'd1));//cnt_clk:时钟周期计数,记录初始化各状态等待时间
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_clk <= 10'd0;else if(cnt_clk_rst == 1'b1)cnt_clk <= 10'd0;elsecnt_clk <= cnt_clk + 1'b1;//trcd_end,trp_end,tcl_end,tread_end,rdburst_end:等待结束标志
assign trcd_end = ((read_state == RD_TRCD) && (cnt_clk == TRCD_CLK)) ? 1'b1 : 1'b0; //行选通周期结束
assign trp_end = ((read_state == RD_TRP ) && (cnt_clk == TRP_CLK)) ? 1'b1 : 1'b0; //预充电有效周期结束
assign tcl_end = ((read_state == RD_CL ) && (cnt_clk == TCL_CLK - 1)) ? 1'b1 : 1'b0; //潜伏期结束
assign tread_end = ((read_state == RD_DATA) && (cnt_clk == rd_burst_len + 2)) ? 1'b1 : 1'b0; //突发读结束
assign rdburst_end = ((read_state == RD_DATA) && (cnt_clk == rd_burst_len - 4)) ? 1'b1 : 1'b0; //读突发终止//read_state:SDRAM的工作状态机
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)read_state <= RD_IDLE;elsecase(read_state)RD_IDLE:if((rd_en ==1'b1) && (init_end == 1'b1))read_state <= RD_ACTIVE;elseread_state <= RD_IDLE;RD_ACTIVE:read_state <= RD_TRCD;RD_TRCD:if(trcd_end == 1'b1)read_state <= RD_READ;elseread_state <= RD_TRCD;RD_READ:read_state <= RD_CL;RD_CL:read_state <= (tcl_end == 1'b1) ? RD_DATA : RD_CL;RD_DATA:read_state <= (tread_end == 1'b1) ? RD_PRE : RD_DATA;RD_PRE:read_state <= RD_TRP;RD_TRP:read_state <= (trp_end == 1'b1) ? RD_END : RD_TRP;RD_END:read_state <= RD_IDLE;default:read_state <= RD_IDLE;endcase//计数器控制逻辑
always@(*)begincase(read_state)RD_IDLE: cnt_clk_rst <= 1'b1;RD_TRCD: cnt_clk_rst <= (trcd_end == 1'b1) ? 1'b1 : 1'b0;RD_READ: cnt_clk_rst <= 1'b1;RD_CL: cnt_clk_rst <= (tcl_end == 1'b1) ? 1'b1 : 1'b0;RD_DATA: cnt_clk_rst <= (tread_end == 1'b1) ? 1'b1 : 1'b0;RD_TRP: cnt_clk_rst <= (trp_end == 1'b1) ? 1'b1 : 1'b0;RD_END: cnt_clk_rst <= 1'b1;default: cnt_clk_rst <= 1'b0;endcaseend//SDRAM操作指令控制
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)beginread_cmd <= NOP;read_ba <= 2'b11;read_addr <= 13'h1fff;endelsecase(read_state)RD_IDLE,RD_TRCD,RD_TRP:beginread_cmd <= NOP;read_ba <= 2'b11;read_addr <= 13'h1fff;endRD_ACTIVE: //激活指令beginread_cmd <= ACTIVE;read_ba <= rd_addr[23:22];read_addr <= rd_addr[21:9];endRD_READ: //读操作指令beginread_cmd <= READ;read_ba <= rd_addr[23:22];read_addr <= {4'b0000,rd_addr[8:0]};endRD_DATA: //突发传输终止指令beginif(rdburst_end == 1'b1)read_cmd <= B_STOP;elsebeginread_cmd <= NOP;read_ba <= 2'b11;read_addr <= 13'h1fff;endendRD_PRE: //预充电指令beginread_cmd <= P_CHARGE;read_ba <= rd_addr[23:22];read_addr <= 13'h0400;endRD_END:beginread_cmd <= NOP;read_ba <= 2'b11;read_addr <= 13'h1fff;enddefault:beginread_cmd <= NOP;read_ba <= 2'b11;read_addr <= 13'h1fff;endendcase//rd_sdram_data:SDRAM读出的数据
assign rd_sdram_data = (rd_ack == 1'b1) ? rd_data_reg : 16'b0;endmodule
`timescale 1ns/1nsmodule sdram_arbit
(input wire sys_clk , //系统时钟input wire sys_rst_n , //复位信号
//sdram_initinput wire [3:0] init_cmd , //初始化阶段命令input wire init_end , //初始化结束标志input wire [1:0] init_ba , //初始化阶段Bank地址input wire [12:0] init_addr , //初始化阶段数据地址
//sdram_auto_refinput wire aref_req , //自刷新请求input wire aref_end , //自刷新结束input wire [3:0] aref_cmd , //自刷新阶段命令input wire [1:0] aref_ba , //自动刷新阶段Bank地址input wire [12:0] aref_addr , //自刷新阶段数据地址
//sdram_writeinput wire wr_req , //写数据请求input wire [1:0] wr_ba , //写阶段Bank地址input wire [15:0] wr_data , //写入SDRAM的数据input wire wr_end , //一次写结束信号input wire [3:0] wr_cmd , //写阶段命令input wire [12:0] wr_addr , //写阶段数据地址input wire wr_sdram_en ,
//sdram_readinput wire rd_req , //读数据请求input wire rd_end , //一次读结束input wire [3:0] rd_cmd , //读阶段命令input wire [12:0] rd_addr , //读阶段数据地址input wire [1:0] rd_ba , //读阶段Bank地址output reg aref_en , //自刷新使能output reg wr_en , //写数据使能output reg rd_en , //读数据使能output wire sdram_cke , //SDRAM时钟使能output wire sdram_cs_n , //SDRAM片选信号output wire sdram_ras_n , //SDRAM行地址选通output wire sdram_cas_n , //SDRAM列地址选通output wire sdram_we_n , //SDRAM写使能output reg [1:0] sdram_ba , //SDRAM Bank地址output reg [12:0] sdram_addr , //SDRAM地址总线inout wire [15:0] sdram_dq //SDRAM数据总线
);//parameter define
parameter IDLE = 5'b0_0001 , //初始状态ARBIT = 5'b0_0010 , //仲裁状态AREF = 5'b0_0100 , //自动刷新状态WRITE = 5'b0_1000 , //写状态READ = 5'b1_0000 ; //读状态
parameter CMD_NOP = 4'b0111 ; //空操作指令//reg define
reg [3:0] sdram_cmd ; //写入SDRAM命令
reg [4:0] state ; //状态机状态//state:状态机状态
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)state <= IDLE;else case(state)IDLE: if(init_end == 1'b1)state <= ARBIT;elsestate <= IDLE;ARBIT: if(aref_req == 1'b1)state <= AREF;else if(wr_req == 1'b1)state <= WRITE;else if(rd_req == 1'b1)state <= READ;elsestate <= ARBIT;AREF: if(aref_end == 1'b1)state <= ARBIT;elsestate <= AREF; WRITE: if(wr_end == 1'b1)state <= ARBIT;elsestate <= WRITE;READ: if(rd_end == 1'b1)state <= ARBIT;elsestate <= READ;default:state <= IDLE;endcase//aref_en:自动刷新使能
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)aref_en <= 1'b0;else if((state == ARBIT) && (aref_req == 1'b1))aref_en <= 1'b1;else if(aref_end == 1'b1)aref_en <= 1'b0;//wr_en:写数据使能
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)wr_en <= 1'b0;else if((state == ARBIT) && (aref_req == 1'b0) && (wr_req == 1'b1))wr_en <= 1'b1;else if(wr_end == 1'b1)wr_en <= 1'b0;//rd_en:读数据使能
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rd_en <= 1'b0;else if((state == ARBIT) && (aref_req == 1'b0) && (rd_req == 1'b1))rd_en <= 1'b1;else if(rd_end == 1'b1)rd_en <= 1'b0;//sdram_cmd:写入SDRAM命令;sdram_ba:SDRAM Bank地址;sdram_addr:SDRAM地址总线
always@(*)case(state) IDLE: beginsdram_cmd <= init_cmd;sdram_ba <= init_ba;sdram_addr <= init_addr;endAREF: beginsdram_cmd <= aref_cmd;sdram_ba <= aref_ba;sdram_addr <= aref_addr;endWRITE: beginsdram_cmd <= wr_cmd;sdram_ba <= wr_ba;sdram_addr <= wr_addr;endREAD: beginsdram_cmd <= rd_cmd;sdram_ba <= rd_ba;sdram_addr <= rd_addr;enddefault: beginsdram_cmd <= CMD_NOP;sdram_ba <= 2'b11;sdram_addr <= 13'h1fff;endendcase//SDRAM时钟使能
assign sdram_cke = 1'b1;
//SDRAM数据总线
assign sdram_dq = (wr_sdram_en == 1'b1) ? wr_data : 16'bz;
//片选信号,行地址选通信号,列地址选通信号,写使能信号
assign {sdram_cs_n, sdram_ras_n, sdram_cas_n, sdram_we_n} = sdram_cmd;endmodule
`timescale 1ns/1nsmodule sdram_ctrl
(input wire sys_clk , //系统时钟input wire sys_rst_n , //复位信号,低电平有效
//SDRAM写端口input wire sdram_wr_req , //写SDRAM请求信号input wire [23:0] sdram_wr_addr , //SDRAM写操作的地址input wire [9:0] wr_burst_len , //写sdram时数据突发长度input wire [15:0] sdram_data_in , //写入SDRAM的数据output wire sdram_wr_ack , //写SDRAM响应信号
//SDRAM读端口input wire sdram_rd_req , //读SDRAM请求信号input wire [23:0] sdram_rd_addr , //SDRAM读操作的地址input wire [9:0] rd_burst_len , //读sdram时数据突发长度output wire [15:0] sdram_data_out , //从SDRAM读出的数据output wire init_end , //SDRAM 初始化完成标志output wire sdram_rd_ack , //读SDRAM响应信号
//FPGA与SDRAM硬件接口output wire sdram_cke , // SDRAM 时钟有效信号output wire sdram_cs_n , // SDRAM 片选信号output wire sdram_ras_n , // SDRAM 行地址选通output wire sdram_cas_n , // SDRAM 列地址选通output wire sdram_we_n , // SDRAM 写使能output wire [1:0] sdram_ba , // SDRAM Bank地址output wire [12:0] sdram_addr , // SDRAM 地址总线inout wire [15:0] sdram_dq // SDRAM 数据总线
);//wire define
//sdram_init
wire [3:0] init_cmd ; //初始化阶段写入sdram的指令
wire [1:0] init_ba ; //初始化阶段Bank地址
wire [12:0] init_addr ; //初始化阶段地址数据,辅助预充电操作
//sdram_a_ref
wire aref_req ; //自动刷新请求
wire aref_end ; //自动刷新结束标志
wire [3:0] aref_cmd ; //自动刷新阶段写入sdram的指令
wire [1:0] aref_ba ; //自动刷新阶段Bank地址
wire [12:0] aref_addr ; //地址数据,辅助预充电操作
wire aref_en ; //自动刷新使能
//sdram_write
wire wr_en ; //写使能
wire wr_end ; //一次写结束信号
wire [3:0] write_cmd ; //写阶段命令
wire [1:0] write_ba ; //写数据阶段Bank地址
wire [12:0] write_addr ; //写阶段数据地址
wire wr_sdram_en ; //SDRAM写使能
wire [15:0] wr_sdram_data; //写入SDRAM的数据
//sdram_read
wire rd_en ; //读使能
wire rd_end ; //一次突发读结束
wire [3:0] read_cmd ; //读数据阶段写入sdram的指令
wire [1:0] read_ba ; //读阶段Bank地址
wire [12:0] read_addr ; //读阶段数据地址//------------- sdram_init_inst -------------
sdram_init sdram_init_inst
(.sys_clk (sys_clk ), //系统时钟,频率100MHz.sys_rst_n (sys_rst_n ), //复位信号,低电平有效.init_cmd (init_cmd ), //初始化阶段写入sdram的指令.init_ba (init_ba ), //初始化阶段Bank地址.init_addr (init_addr ), //初始化阶段地址数据,辅助预充电操作.init_end (init_end ) //初始化结束信号
);//------------- sdram_arbit_inst -------------
sdram_arbit sdram_arbit_inst
(.sys_clk (sys_clk ), //系统时钟.sys_rst_n (sys_rst_n ), //复位信号
//sdram_init.init_cmd (init_cmd ), //初始化阶段命令.init_end (init_end ), //初始化结束标志.init_ba (init_ba ), //初始化阶段Bank地址.init_addr (init_addr ), //初始化阶段数据地址
//sdram_auto_ref.aref_req (aref_req ), //自刷新请求.aref_end (aref_end ), //自刷新结束.aref_cmd (aref_cmd ), //自刷新阶段命令.aref_ba (aref_ba ), //自动刷新阶段Bank地址.aref_addr (aref_addr ), //自刷新阶段数据地址
//sdram_write.wr_req (sdram_wr_req ), //写数据请求.wr_end (wr_end ), //一次写结束信号.wr_cmd (write_cmd ), //写阶段命令.wr_ba (write_ba ), //写阶段Bank地址.wr_addr (write_addr ), //写阶段数据地址.wr_sdram_en(wr_sdram_en ), //SDRAM写使能.wr_data (wr_sdram_data ), //写入SDRAM的数据
//sdram_read.rd_req (sdram_rd_req ), //读数据请求.rd_end (rd_end ), //一次读结束.rd_cmd (read_cmd ), //读阶段命令.rd_addr (read_addr ), //读阶段数据地址.rd_ba (read_ba ), //读阶段Bank地址.aref_en (aref_en ), //自刷新使能.wr_en (wr_en ), //写数据使能.rd_en (rd_en ), //读数据使能.sdram_cke (sdram_cke ), //SDRAM时钟使能.sdram_cs_n (sdram_cs_n ), //SDRAM片选信号.sdram_ras_n(sdram_ras_n ), //SDRAM行地址选通.sdram_cas_n(sdram_cas_n ), //SDRAM列地址选通.sdram_we_n (sdram_we_n ), //SDRAM写使能.sdram_ba (sdram_ba ), //SDRAM Bank地址.sdram_addr (sdram_addr ), //SDRAM地址总线.sdram_dq (sdram_dq ) //SDRAM数据总线
);//------------- sdram_a_ref_inst -------------
sdram_a_ref sdram_a_ref_inst
(.sys_clk (sys_clk ), //系统时钟,频率100MHz.sys_rst_n (sys_rst_n ), //复位信号,低电平有效.init_end (init_end ), //初始化结束信号.aref_en (aref_en ), //自动刷新使能.aref_req (aref_req ), //自动刷新请求.aref_cmd (aref_cmd ), //自动刷新阶段写入sdram的指令.aref_ba (aref_ba ), //自动刷新阶段Bank地址.aref_addr (aref_addr ), //地址数据,辅助预充电操作.aref_end (aref_end ) //自动刷新结束标志
);//------------- sdram_write_inst -------------
sdram_write sdram_write_inst
(.sys_clk (sys_clk ), //系统时钟,频率100MHz.sys_rst_n (sys_rst_n ), //复位信号,低电平有效.init_end (init_end ), //初始化结束信号.wr_en (wr_en ), //写使能.wr_addr (sdram_wr_addr ), //写SDRAM地址.wr_data (sdram_data_in ), //待写入SDRAM的数据(写FIFO传入).wr_burst_len (wr_burst_len ), //写突发SDRAM字节数.wr_ack (sdram_wr_ack ), //写SDRAM响应信号.wr_end (wr_end ), //一次突发写结束.write_cmd (write_cmd ), //写数据阶段写入sdram的指令.write_ba (write_ba ), //写数据阶段Bank地址.write_addr (write_addr ), //地址数据,辅助预充电操作.wr_sdram_en (wr_sdram_en ), //数据总线输出使能.wr_sdram_data (wr_sdram_data ) //写入SDRAM的数据
);//------------- sdram_read_inst -------------
sdram_read sdram_read_inst
(.sys_clk (sys_clk ), //系统时钟,频率100MHz.sys_rst_n (sys_rst_n ), //复位信号,低电平有效.init_end (init_end ), //初始化结束信号.rd_en (rd_en ), //读使能.rd_addr (sdram_rd_addr ), //读SDRAM地址.rd_data (sdram_dq ), //自SDRAM中读出的数据.rd_burst_len (rd_burst_len ), //读突发SDRAM字节数.rd_ack (sdram_rd_ack ), //读SDRAM响应信号.rd_end (rd_end ), //一次突发读结束.read_cmd (read_cmd ), //读数据阶段写入sdram的指令.read_ba (read_ba ), //读数据阶段Bank地址.read_addr (read_addr ), //地址数据,辅助预充电操作.rd_sdram_data (sdram_data_out ) //SDRAM读出的数据
);endmodule
`timescale 1ns/1nsmodule fifo_ctrl
(input wire sys_clk , //系统时钟input wire sys_rst_n , //复位信号
//写fifo信号input wire wr_fifo_wr_clk , //写FIFO写时钟input wire wr_fifo_wr_req , //写FIFO写请求input wire [15:0] wr_fifo_wr_data , //写FIFO写数据input wire [23:0] sdram_wr_b_addr , //写SDRAM首地址input wire [23:0] sdram_wr_e_addr , //写SDRAM末地址input wire [9:0] wr_burst_len , //写SDRAM数据突发长度input wire wr_rst , //写复位信号
//读fifo信号input wire rd_fifo_rd_clk , //读FIFO读时钟input wire rd_fifo_rd_req , //读FIFO读请求input wire [23:0] sdram_rd_b_addr , //读SDRAM首地址input wire [23:0] sdram_rd_e_addr , //读SDRAM末地址input wire [9:0] rd_burst_len , //读SDRAM数据突发长度input wire rd_rst , //读复位信号output wire [15:0] rd_fifo_rd_data , //读FIFO读数据output wire [9:0] rd_fifo_num , //读fifo中的数据量input wire read_valid , //SDRAM读使能input wire init_end , //SDRAM初始化完成标志
//SDRAM写信号input wire sdram_wr_ack , //SDRAM写响应output reg sdram_wr_req , //SDRAM写请求output reg [23:0] sdram_wr_addr , //SDRAM写地址output wire [15:0] sdram_data_in , //写入SDRAM的数据
//SDRAM读信号input wire sdram_rd_ack , //SDRAM读相应input wire [15:0] sdram_data_out , //读出SDRAM数据output reg sdram_rd_req , //SDRAM读请求output reg [23:0] sdram_rd_addr //SDRAM读地址
);//wire define
wire wr_ack_fall ; //写响应信号下降沿
wire rd_ack_fall ; //读相应信号下降沿
wire [9:0] wr_fifo_num ; //写fifo中的数据量//reg define
reg wr_ack_dly ; //写响应打拍
reg rd_ack_dly ; //读响应打拍//wr_ack_dly:写响应信号打拍
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)wr_ack_dly <= 1'b0;elsewr_ack_dly <= sdram_wr_ack;//rd_ack_dly:读响应信号打拍
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rd_ack_dly <= 1'b0;elserd_ack_dly <= sdram_rd_ack;//wr_ack_fall,rd_ack_fall:检测读写响应信号下降沿
assign wr_ack_fall = (wr_ack_dly & ~sdram_wr_ack);
assign rd_ack_fall = (rd_ack_dly & ~sdram_rd_ack);//sdram_wr_addr:sdram写地址
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)sdram_wr_addr <= 24'd0;else if(wr_rst == 1'b1)sdram_wr_addr <= sdram_wr_b_addr;else if(wr_ack_fall == 1'b1) //一次突发写结束,更改写地址beginif(sdram_wr_addr < (sdram_wr_e_addr - wr_burst_len))//不使用乒乓操作,一次突发写结束,更改写地址,未达到末地址,写地址累加sdram_wr_addr <= sdram_wr_addr + wr_burst_len;else //不使用乒乓操作,到达末地址,回到写起始地址sdram_wr_addr <= sdram_wr_b_addr;end//sdram_rd_addr:sdram读地址
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)sdram_rd_addr <= 24'd0;else if(rd_rst == 1'b1)sdram_rd_addr <= sdram_rd_b_addr;else if(rd_ack_fall == 1'b1) //一次突发读结束,更改读地址beginif(sdram_rd_addr < (sdram_rd_e_addr - rd_burst_len))//读地址未达到末地址,读地址累加sdram_rd_addr <= sdram_rd_addr + rd_burst_len;else //到达末地址,回到首地址sdram_rd_addr <= sdram_rd_b_addr;end//sdram_wr_req,sdram_rd_req:读写请求信号
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)beginsdram_wr_req <= 1'b0;sdram_rd_req <= 1'b0;endelse if(init_end == 1'b1) //初始化完成后响应读写请求begin //优先执行写操作,防止写入SDRAM中的数据丢失if(wr_fifo_num >= wr_burst_len)begin //写FIFO中的数据量达到写突发长度sdram_wr_req <= 1'b1; //写请求有效sdram_rd_req <= 1'b0;endelse if((rd_fifo_num < rd_burst_len) && (read_valid == 1'b1))begin //读FIFO中的数据量小于读突发长度,且读使能信号有效sdram_wr_req <= 1'b0;sdram_rd_req <= 1'b1; //读请求有效endelsebeginsdram_wr_req <= 1'b0;sdram_rd_req <= 1'b0;endendelsebeginsdram_wr_req <= 1'b0;sdram_rd_req <= 1'b0;end//------------- wr_fifo_data -------------
fifo_data wr_fifo_data(//用户接口.wrclk (wr_fifo_wr_clk ), //写时钟.wrreq (wr_fifo_wr_req ), //写请求.data (wr_fifo_wr_data), //写数据//SDRAM接口.rdclk (sys_clk ), //读时钟.rdreq (sdram_wr_ack ), //读请求.q (sdram_data_in ), //读数据.rdusedw (wr_fifo_num ), //FIFO中的数据量.wrusedw ( ),.aclr (~sys_rst_n || wr_rst) //清零信号);//------------- rd_fifo_data -------------
fifo_data rd_fifo_data(//sdram接口.wrclk (sys_clk ), //写时钟.wrreq (sdram_rd_ack ), //写请求.data (sdram_data_out ), //写数据//用户接口.rdclk (rd_fifo_rd_clk ), //读时钟.rdreq (rd_fifo_rd_req ), //读请求.q (rd_fifo_rd_data), //读数据.rdusedw ( ),.wrusedw (rd_fifo_num ), //FIFO中的数据量.aclr (~sys_rst_n || rd_rst) //清零信号);endmodule
`timescale 1ns/1nsmodule sdram_top
(input wire sys_clk , //系统时钟input wire clk_out , //相位偏移时钟input wire sys_rst_n , //复位信号,低有效
//写FIFO信号input wire wr_fifo_wr_clk , //写FIFO写时钟input wire wr_fifo_wr_req , //写FIFO写请求input wire [15:0] wr_fifo_wr_data , //写FIFO写数据input wire [23:0] sdram_wr_b_addr , //写SDRAM首地址input wire [23:0] sdram_wr_e_addr , //写SDRAM末地址input wire [9:0] wr_burst_len , //写SDRAM数据突发长度input wire wr_rst , //写复位信号
//读FIFO信号input wire rd_fifo_rd_clk , //读FIFO读时钟input wire rd_fifo_rd_req , //读FIFO读请求input wire [23:0] sdram_rd_b_addr , //读SDRAM首地址input wire [23:0] sdram_rd_e_addr , //读SDRAM末地址input wire [9:0] rd_burst_len , //读SDRAM数据突发长度input wire rd_rst , //读复位信号output wire [15:0] rd_fifo_rd_data , //读FIFO读数据output wire [9:0] rd_fifo_num , //读fifo中的数据量input wire read_valid , //SDRAM读使能output wire init_end , //SDRAM初始化完成标志
//SDRAM接口信号output wire sdram_clk , //SDRAM芯片时钟output wire sdram_cke , //SDRAM时钟有效信号output wire sdram_cs_n , //SDRAM片选信号output wire sdram_ras_n , //SDRAM行地址选通脉冲output wire sdram_cas_n , //SDRAM列地址选通脉冲output wire sdram_we_n , //SDRAM写允许位output wire [1:0] sdram_ba , //SDRAM的L-Bank地址线output wire [12:0] sdram_addr , //SDRAM地址总线output wire [1:0] sdram_dqm , //SDRAM数据掩码inout wire [15:0] sdram_dq //SDRAM数据总线
);//wire define
wire sdram_wr_req ; //sdram 写请求
wire sdram_wr_ack ; //sdram 写响应
wire [23:0] sdram_wr_addr ; //sdram 写地址
wire [15:0] sdram_data_in ; //写入sdram中的数据wire sdram_rd_req ; //sdram 读请求
wire sdram_rd_ack ; //sdram 读响应
wire [23:0] sdram_rd_addr ; //sdram 读地址
wire [15:0] sdram_data_out ; //从sdram中读出的数据//sdram_clk:SDRAM芯片时钟
assign sdram_clk = clk_out;
//sdram_dqm:SDRAM数据掩码
assign sdram_dqm = 2'b00;//------------- fifo_ctrl_inst -------------
fifo_ctrl fifo_ctrl_inst(//system signal.sys_clk (sys_clk ), //SDRAM控制时钟.sys_rst_n (sys_rst_n ), //复位信号
//write fifo signal.wr_fifo_wr_clk (wr_fifo_wr_clk ), //写FIFO写时钟.wr_fifo_wr_req (wr_fifo_wr_req ), //写FIFO写请求.wr_fifo_wr_data(wr_fifo_wr_data), //写FIFO写数据.sdram_wr_b_addr(sdram_wr_b_addr), //写SDRAM首地址.sdram_wr_e_addr(sdram_wr_e_addr), //写SDRAM末地址.wr_burst_len (wr_burst_len ), //写SDRAM数据突发长度.wr_rst (wr_rst ), //写清零信号
//read fifo signal.rd_fifo_rd_clk (rd_fifo_rd_clk ), //读FIFO读时钟.rd_fifo_rd_req (rd_fifo_rd_req ), //读FIFO读请求.rd_fifo_rd_data(rd_fifo_rd_data), //读FIFO读数据.rd_fifo_num (rd_fifo_num ), //读FIFO中的数据量.sdram_rd_b_addr(sdram_rd_b_addr), //读SDRAM首地址.sdram_rd_e_addr(sdram_rd_e_addr), //读SDRAM末地址.rd_burst_len (rd_burst_len ), //读SDRAM数据突发长度.rd_rst (rd_rst ), //读清零信号
//USER ctrl signal.read_valid (read_valid ), //SDRAM读使能.init_end (init_end ), //SDRAM初始化完成标志
//SDRAM ctrl of write.sdram_wr_ack (sdram_wr_ack ), //SDRAM写响应.sdram_wr_req (sdram_wr_req ), //SDRAM写请求.sdram_wr_addr (sdram_wr_addr ), //SDRAM写地址.sdram_data_in (sdram_data_in ), //写入SDRAM的数据
//SDRAM ctrl of read.sdram_rd_ack (sdram_rd_ack ), //SDRAM读请求.sdram_data_out (sdram_data_out ), //SDRAM读响应.sdram_rd_req (sdram_rd_req ), //SDRAM读地址.sdram_rd_addr (sdram_rd_addr ) //读出SDRAM数据
);//------------- sdram_ctrl_inst -------------
sdram_ctrl sdram_ctrl_inst(.sys_clk (sys_clk ), //系统时钟.sys_rst_n (sys_rst_n ), //复位信号,低电平有效
//SDRAM 控制器写端口.sdram_wr_req (sdram_wr_req ), //写SDRAM请求信号.sdram_wr_addr (sdram_wr_addr ), //SDRAM写操作的地址.wr_burst_len (wr_burst_len ), //写sdram时数据突发长度.sdram_data_in (sdram_data_in ), //写入SDRAM的数据.sdram_wr_ack (sdram_wr_ack ), //写SDRAM响应信号
//SDRAM 控制器读端口.sdram_rd_req (sdram_rd_req ), //读SDRAM请求信号.sdram_rd_addr (sdram_rd_addr ), //SDRAM写操作的地址.rd_burst_len (rd_burst_len ), //读sdram时数据突发长度.sdram_data_out (sdram_data_out ), //从SDRAM读出的数据.init_end (init_end ), //SDRAM 初始化完成标志.sdram_rd_ack (sdram_rd_ack ), //读SDRAM响应信号
//FPGA与SDRAM硬件接口.sdram_cke (sdram_cke ), // SDRAM 时钟有效信号.sdram_cs_n (sdram_cs_n ), // SDRAM 片选信号.sdram_ras_n (sdram_ras_n ), // SDRAM 行地址选通脉冲.sdram_cas_n (sdram_cas_n ), // SDRAM 列地址选通脉冲.sdram_we_n (sdram_we_n ), // SDRAM 写允许位.sdram_ba (sdram_ba ), // SDRAM L-Bank地址线.sdram_addr (sdram_addr ), // SDRAM 地址总线.sdram_dq (sdram_dq ) // SDRAM 数据总线
);endmodule
`timescale 1ns/1nsmodule uart_rx
#(parameter UART_BPS = 'd9600, //串口波特率parameter CLK_FREQ = 'd50_000_000 //时钟频率
)
(input wire sys_clk , //系统时钟50MHzinput wire sys_rst_n , //全局复位input wire rx , //串口接收数据output reg [7:0] po_data , //串转并后的8bit数据output reg po_flag //串转并后的数据有效标志信号
);//localparam define
localparam BAUD_CNT_MAX = CLK_FREQ/UART_BPS ;//reg define
reg rx_reg1 ;
reg rx_reg2 ;
reg rx_reg3 ;
reg start_nedge ;
reg work_en ;
reg [12:0] baud_cnt ;
reg bit_flag ;
reg [3:0] bit_cnt ;
reg [7:0] rx_data ;
reg rx_flag ;//插入两级寄存器进行数据同步,用来消除亚稳态
//rx_reg1:第一级寄存器,寄存器空闲状态复位为1
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rx_reg1 <= 1'b1;elserx_reg1 <= rx;//rx_reg2:第二级寄存器,寄存器空闲状态复位为1
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rx_reg2 <= 1'b1;elserx_reg2 <= rx_reg1;//rx_reg3:第三级寄存器和第二级寄存器共同构成下降沿检测
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rx_reg3 <= 1'b1;elserx_reg3 <= rx_reg2;//start_nedge:检测到下降沿时start_nedge产生一个时钟的高电平
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)start_nedge <= 1'b0;else if((~rx_reg2) && (rx_reg3))start_nedge <= 1'b1;elsestart_nedge <= 1'b0;//work_en:接收数据工作使能信号
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)work_en <= 1'b0;else if(start_nedge == 1'b1)work_en <= 1'b1;else if((bit_cnt == 4'd8) && (bit_flag == 1'b1))work_en <= 1'b0;//baud_cnt:波特率计数器计数,从0计数到BAUD_CNT_MAX - 1
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)baud_cnt <= 13'b0;else if((baud_cnt == BAUD_CNT_MAX - 1) || (work_en == 1'b0))baud_cnt <= 13'b0;else if(work_en == 1'b1)baud_cnt <= baud_cnt + 1'b1;//bit_flag:当baud_cnt计数器计数到中间数时采样的数据最稳定,
//此时拉高一个标志信号表示数据可以被取走
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)bit_flag <= 1'b0;else if(baud_cnt == BAUD_CNT_MAX/2 - 1)bit_flag <= 1'b1;elsebit_flag <= 1'b0;//bit_cnt:有效数据个数计数器,当8个有效数据(不含起始位和停止位)
//都接收完成后计数器清零
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)bit_cnt <= 4'b0;else if((bit_cnt == 4'd8) && (bit_flag == 1'b1))bit_cnt <= 4'b0;else if(bit_flag ==1'b1)bit_cnt <= bit_cnt + 1'b1;//rx_data:输入数据进行移位
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rx_data <= 8'b0;else if((bit_cnt >= 4'd1)&&(bit_cnt <= 4'd8)&&(bit_flag == 1'b1))rx_data <= {rx_reg3, rx_data[7:1]};//rx_flag:输入数据移位完成时rx_flag拉高一个时钟的高电平
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rx_flag <= 1'b0;else if((bit_cnt == 4'd8) && (bit_flag == 1'b1))rx_flag <= 1'b1;elserx_flag <= 1'b0;//po_data:输出完整的8位有效数据
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)po_data <= 8'b0;else if(rx_flag == 1'b1)po_data <= rx_data;//po_flag:输出数据有效标志(比rx_flag延后一个时钟周期,为了和po_data同步)
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)po_flag <= 1'b0;elsepo_flag <= rx_flag;endmodule
`timescale 1ns/1nsmodule uart_tx
#(parameter UART_BPS = 'd9600, //串口波特率parameter CLK_FREQ = 'd50_000_000 //时钟频率
)
(input wire sys_clk , //系统时钟50MHzinput wire sys_rst_n , //全局复位input wire [7:0] pi_data , //模块输入的8bit数据input wire pi_flag , //并行数据有效标志信号output reg tx //串转并后的1bit数据
);//localparam define
localparam BAUD_CNT_MAX = CLK_FREQ/UART_BPS ;//reg define
reg [12:0] baud_cnt;
reg bit_flag;
reg [3:0] bit_cnt ;
reg work_en ;//work_en:接收数据工作使能信号
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)work_en <= 1'b0;else if(pi_flag == 1'b1)work_en <= 1'b1;else if((bit_flag == 1'b1) && (bit_cnt == 4'd9))work_en <= 1'b0;//baud_cnt:波特率计数器计数,从0计数到BAUD_CNT_MAX - 1
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)baud_cnt <= 13'b0;else if((baud_cnt == BAUD_CNT_MAX - 1) || (work_en == 1'b0))baud_cnt <= 13'b0;else if(work_en == 1'b1)baud_cnt <= baud_cnt + 1'b1;//bit_flag:当baud_cnt计数器计数到1时让bit_flag拉高一个时钟的高电平
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)bit_flag <= 1'b0;else if(baud_cnt == 13'd1)bit_flag <= 1'b1;elsebit_flag <= 1'b0;//bit_cnt:数据位数个数计数,10个有效数据(含起始位和停止位)到来后计数器清零
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)bit_cnt <= 4'b0;else if((bit_flag == 1'b1) && (bit_cnt == 4'd9))bit_cnt <= 4'b0;else if((bit_flag == 1'b1) && (work_en == 1'b1))bit_cnt <= bit_cnt + 1'b1;//tx:输出数据在满足rs232协议(起始位为0,停止位为1)的情况下一位一位输出
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)tx <= 1'b1; //空闲状态时为高电平else if(bit_flag == 1'b1)case(bit_cnt)0 : tx <= 1'b0;1 : tx <= pi_data[0];2 : tx <= pi_data[1];3 : tx <= pi_data[2];4 : tx <= pi_data[3];5 : tx <= pi_data[4];6 : tx <= pi_data[5];7 : tx <= pi_data[6];8 : tx <= pi_data[7];9 : tx <= 1'b1;default : tx <= 1'b1;endcaseendmodule
`timescale 1ns/1nsmodule fifo_read
(input wire sys_clk , //系统时钟,频率50MHzinput wire sys_rst_n , //复位信号,低电平有效input wire [9:0] rd_fifo_num , //SDRAM中读fifo中数据个数input wire [7:0] pi_data , //读出数据input wire [9:0] burst_num , //一次突发数据个数output reg read_en , //SDRAM中读fifo的读使能output wire [7:0] tx_data , //输出数据output reg tx_flag //输出数据标志信号
);//parameter define
parameter BAUD_CNT_END = 13'd5207 ,BAUD_CNT_END_HALF = 13'd2603 ;
parameter CNT_WAIT_MAX = 24'd4_999_999 ;//wire define
wire [9:0] data_num ; //fifo中数据个数//reg define
reg read_en_dly ;
reg [12:0] baud_cnt ;
reg rd_en ;
reg rd_flag ;
reg [9:0] cnt_read ;
reg [3:0] bit_cnt ;
reg bit_flag ;//read_en:SDRAM中读fifo的读使能
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)read_en <= 1'b0;else if(rd_fifo_num == burst_num)read_en <= 1'b1;else if(data_num == burst_num - 2)read_en <= 1'b0;//read_en_dly:SDRAM中读fifo的读使能打拍
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)read_en_dly <= 1'b0;elseread_en_dly <= read_en;//rd_flag:向tx模块发送数据使能
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rd_flag <= 1'b0;else if(cnt_read == burst_num)rd_flag <= 1'b0;else if(data_num == burst_num)rd_flag <= 1'b1;//baud_cnt:波特率计数器计数从0计数到BAUD_CNT_END
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)baud_cnt <= 13'd0;else if(baud_cnt == BAUD_CNT_END)baud_cnt <= 13'd0;else if(rd_flag == 1'b1)baud_cnt <= baud_cnt + 1'b1;//bit_flag:bit计数器计数使能
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)bit_flag <= 1'b0;else if(baud_cnt == BAUD_CNT_END_HALF)bit_flag <= 1'b1;elsebit_flag <= 1'b0;//bit_cnt:bit计数器
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)bit_cnt <= 4'b0;else if((bit_cnt == 4'd9) && (bit_flag == 1'b1))bit_cnt <= 4'b0;else if(bit_flag == 1'b1)bit_cnt <= bit_cnt + 1'b1;//rd_en:读fifo的读使能
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)rd_en <= 1'b0;else if(bit_cnt == 4'd9 && bit_flag == 1'b1)rd_en <= 1'b1;elserd_en <= 1'b0;//cnt_read:读出数据计数
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_read <= 10'd0;else if(cnt_read == burst_num)cnt_read <= 10'b0;else if(rd_en == 1'b1)cnt_read <= cnt_read + 1'b1;elsecnt_read <= cnt_read;//tx_flag:读出数据标志信号
always@(posedge sys_clk or negedge sys_rst_n)if(sys_rst_n == 1'b0)tx_flag <= 1'b0;elsetx_flag <= rd_en;//-------------fifo_read_inst--------------
read_fifo read_fifo_inst(.clock (sys_clk ), //input clk.data (pi_data ), //input [7 : 0] din.wrreq (read_en_dly ), //input wr_en.rdreq (rd_en ), //input rd_en.q (tx_data ), //output [7 : 0] dout.usedw (data_num )
);endmodule
`timescale 1ns/1nsmodule uart_sdram
(input wire sys_clk , //时钟信号input wire sys_rst_n , //复位信号input wire rx , //串口接收数据output wire tx , //串口发送数据output wire sdram_clk , //SDRAM 芯片时钟output wire sdram_cke , //SDRAM 时钟有效output wire sdram_cs_n , //SDRAM 片选output wire sdram_cas_n , //SDRAM 行有效output wire sdram_ras_n , //SDRAM 列有效output wire sdram_we_n , //SDRAM 写有效output wire [1:0] sdram_ba , //SDRAM Bank地址output wire [12:0] sdram_addr , //SDRAM 行/列地址output wire [1:0] sdram_dqm , //SDRAM 数据掩码inout wire [15:0] sdram_dq //SDRAM 数据
);//parameter define
parameter DATA_NUM = 24'd10 ; //写入SDRAM数据个数
parameter WAIT_MAX = 16'd750 ; //等待计数最大值
parameter UART_BPS = 14'd9600 , //比特率CLK_FREQ = 26'd50_000_000 ; //时钟频率// wire define
//uart_rx
wire [ 7:0] rx_data ; //串口接收模块拼接后的8位数据
wire rx_flag ; //数据标志信号//fifo_read
wire [ 7:0] rfifo_wr_data ; //读fifo发热写入数据
wire rfifo_wr_en ; //读fifo的写使能
wire [ 7:0] rfifo_rd_data ; //读fifo的读数据
wire rfifo_rd_en ; //读fifo的读使能
wire [9:0] rd_fifo_num ; //读fifo中的数据量//clk_gen
wire clk_50m ;
wire clk_100m ;
wire clk_100m_shift ; //pll产生时钟
wire locked ; //pll锁定信号
wire rst_n ; //复位信号//sdram_top_inst
reg [23:0] data_num ; //写入SDRAM数据个数计数
reg read_valid ; //数据读使能
reg [15:0] cnt_wait ; //等待计数器//rst_n:复位信号
assign rst_n = sys_rst_n & locked;//data_num:写入SDRAM数据个数计数
always@(posedge clk_50m or negedge sys_rst_n)if(sys_rst_n == 1'b0)data_num <= 24'd0;else if(read_valid == 1'b1)data_num <= 24'd0;else if(rx_flag == 1'b1)data_num <= data_num + 1'b1;elsedata_num <= data_num;//cnt_wait:等待计数器
always@(posedge clk_50m or negedge sys_rst_n)if(sys_rst_n == 1'b0)cnt_wait <= 16'd0;else if(cnt_wait == WAIT_MAX)cnt_wait <= 16'd0;else if(data_num == DATA_NUM)cnt_wait <= cnt_wait + 1'b1;//read_valid:数据读使能
always@(posedge clk_50m or negedge sys_rst_n)if(sys_rst_n == 1'b0)read_valid <= 1'b0;else if(cnt_wait == WAIT_MAX)read_valid <= 1'b1;else if(rd_fifo_num == DATA_NUM)read_valid <= 1'b0;//------------- clk_gen_inst -------------
clk_gen clk_gen_inst (.inclk0 (sys_clk ),.areset (~sys_rst_n ),.c0 (clk_50m ),.c1 (clk_100m ),.c2 (clk_100m_shift ),.locked (locked )
);//-------------uart_rx_inst-------------
uart_rx
#(.UART_BPS (UART_BPS ), //串口波特率.CLK_FREQ (CLK_FREQ ) //时钟频率
)
uart_rx_inst
(.sys_clk (clk_50m ), //input sys_clk.sys_rst_n (rst_n ), //input sys_rst_n.rx (rx ), //input rx.po_data (rx_data ), //output [7:0] rx_data.po_flag (rx_flag ) //output rx_flag
);//------------- sdram_top_inst -------------
sdram_top sdram_top_inst
(.sys_clk (clk_100m ), //sdram 控制器参考时钟.clk_out (clk_100m_shift ), //用于输出的相位偏移时钟.sys_rst_n (rst_n ), //系统复位
//用户写端口.wr_fifo_wr_clk (clk_50m ), //写端口FIFO: 写时钟.wr_fifo_wr_req (rx_flag ), //写端口FIFO: 写使能.wr_fifo_wr_data ({8'b0,rx_data} ), //写端口FIFO: 写数据.sdram_wr_b_addr (24'd0 ), //写SDRAM的起始地址.sdram_wr_e_addr (DATA_NUM ), //写SDRAM的结束地址.wr_burst_len (DATA_NUM ), //写SDRAM时的数据突发长度.wr_rst ( ), //写复位
//用户读端口.rd_fifo_rd_clk (clk_50m ), //读端口FIFO: 读时钟.rd_fifo_rd_req (rfifo_wr_en ), //读端口FIFO: 读使能.rd_fifo_rd_data (rfifo_wr_data ), //读端口FIFO: 读数据.sdram_rd_b_addr (24'd0 ), //读SDRAM的起始地址.sdram_rd_e_addr (DATA_NUM ), //读SDRAM的结束地址.rd_burst_len (DATA_NUM ), //从SDRAM中读数据时的突发长度.rd_rst ( ), //读复位.rd_fifo_num (rd_fifo_num ), //读fifo中的数据量
//用户控制端口.read_valid (read_valid ), //SDRAM 读使能.init_end ( ), //SDRAM 初始化完成标志
//SDRAM 芯片接口.sdram_clk (sdram_clk ), //SDRAM 芯片时钟.sdram_cke (sdram_cke ), //SDRAM 时钟有效.sdram_cs_n (sdram_cs_n ), //SDRAM 片选.sdram_ras_n (sdram_ras_n ), //SDRAM 行有效.sdram_cas_n (sdram_cas_n ), //SDRAM 列有效.sdram_we_n (sdram_we_n ), //SDRAM 写有效.sdram_ba (sdram_ba ), //SDRAM Bank地址.sdram_addr (sdram_addr ), //SDRAM 行/列地址.sdram_dq (sdram_dq ), //SDRAM 数据.sdram_dqm (sdram_dqm ) //SDRAM 数据掩码
);//------------- fifo_read_inst --------------
fifo_read fifo_read_inst
(.sys_clk (clk_50m ), //input sys_clk.sys_rst_n (sys_rst_n ), //input sys_rst_n.rd_fifo_num (rd_fifo_num ),.pi_data (rfifo_wr_data ), //input [7:0] pi_data.burst_num (DATA_NUM ),.read_en (rfifo_wr_en ), //input pi_flag.tx_data (rfifo_rd_data ), //output [7:0] tx_data.tx_flag (rfifo_rd_en ) //output tx_flag
);//-------------uart_tx_inst-------------
uart_tx
#(.UART_BPS (UART_BPS ), //串口波特率.CLK_FREQ (CLK_FREQ ) //时钟频率
)
uart_tx_inst
(.sys_clk (sys_clk ), //input sys_clk.sys_rst_n (sys_rst_n ), //input sys_rst_n.pi_data (rfifo_rd_data ), //input [7:0] pi_data.pi_flag (rfifo_rd_en ), //input pi_flag.tx (tx ) //output tx
);endmodule
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