北京做网站便宜的公司,网页设计作业之玩具商城网站,烟台微信公众号开发,做外贸网站流程图一#xff0c;为什么做仲裁
在多主单从的设计中#xff0c;当多个源端同时发起传输请求时#xff0c;这个时候就需要仲裁器来根据优先级来判断响应哪一个源端#xff0c;向其传输数据。比如#xff1a;以太网仲裁#xff0c;DDR仲裁#xff0c;光纤传图仲裁.....
二为什么做仲裁
在多主单从的设计中当多个源端同时发起传输请求时这个时候就需要仲裁器来根据优先级来判断响应哪一个源端向其传输数据。比如以太网仲裁DDR仲裁光纤传图仲裁.....
二仲裁类别
仲裁器分为轮询仲裁(Round-Robiin)与固定优先级仲裁(Fixed-Priority)轮询仲裁各个源端优先级相同当同时发起请求时依次进行响应而固定优先级仲裁就是根据优先级顺序依次进行响应。
轮询仲裁每一路数据的优先级都是一样的
中断仲裁有一路或者多路的优先级是最高的
用的比较多的方法就是轮询仲裁
三轮询仲裁
在实际项目中如果需要用到仲裁可以以2路数据作为分析
① 缓存每一路的数据 使用两个FIFO 数据FIFO缓存datalastlast信号的作用指示每一帧数据的边界 控制FIFO缓存缓存数据对应的信息类型、地址、长度……
② 设计状态机轮询跳变 复位状态机处于IDLE复位结束调到发送通道0的状态 发送通道0状态开始判断通道0的数据有没有来询问如果通道0没有来数据则调到通道1。 如果通道0有数据来则把通道0的数据从FIFO里面读出来发送出去然后跳到通道1。 发送通道1状态开始判断通道1的数据有没有来询问如果通道1没有来数据则调到通道2。 如果通道1有数据来则把通道1的数据从FIFO里面读出来发送出去然后跳到通道2。 …….
四轮询仲裁逻辑设计
以2通道设计为例
timescale 1ns / 1psmodule mux2_arbit(input clk ,input reset ,input [15:0] ch0_type , //默认所有通道传来的信号都是reg型所以进行无需打拍input [15:0] ch0_length ,input ch0_data_vld ,input ch0_data_last ,input [7:0] ch0_data ,input [15:0] ch1_type ,input [15:0] ch1_length ,input ch1_data_vld ,input ch1_data_last ,input [7:0] ch1_data ,output reg [15:0] send_type ,output reg [15:0] send_length ,output reg send_data_vld ,output reg send_data_last ,output reg [7:0] send_data );
/*--------------------------------------------------*\状态机信号定义
\*--------------------------------------------------*/
reg [2:0] cur_status;
reg [2:0] nxt_status;
localparam IDLE 2b00;
localparam CH0_SEND 2b01;
localparam CH1_SEND 2b10;
/*--------------------------------------------------*\FIFO端口信号
\*--------------------------------------------------*/
reg [31:0] ch0_frame_din ;
reg ch0_frame_wren ;
wire [31:0] ch0_frame_dout ;
reg ch0_frame_rden ;
wire ch0_frame_wrfull ;
wire ch0_frame_rdempty;
wire [4:0] ch0_frame_count ;reg [31:0] ch1_frame_din ;
reg ch1_frame_wren ;
wire [31:0] ch1_frame_dout ;
reg ch1_frame_rden ;
wire ch1_frame_wrfull ;
wire ch1_frame_rdempty;
wire [4:0] ch1_frame_count ;reg [8:0] ch0_data_din ;
reg ch0_data_wren ;
wire [8:0] ch0_data_dout ;
reg ch0_data_rden ;
wire ch0_data_wrfull ;
wire ch0_data_rdempty;
wire [11:0] ch0_data_count ;reg [8:0] ch1_data_din ;
reg ch1_data_wren ;
wire [8:0] ch1_data_dout ;
reg ch1_data_rden ;
wire ch1_data_wrfull ;
wire ch1_data_rdempty;
wire [11:0] ch1_data_count ;/*--------------------------------------------------*\其他端口信号
\*--------------------------------------------------*/
reg ch0_busy;
reg ch1_busy;reg ch0_frame_fifo_err;
reg ch1_frame_fifo_err;
reg ch0_data_fifo_err ;
reg ch1_data_fifo_err ;/*--------------------------------------------------*\通道0、通道1的数据写入FIFO
\*--------------------------------------------------*/
always (posedge clk) beginch0_frame_wren ch0_data_last;ch0_frame_din {ch0_type,ch0_length};ch1_frame_wren ch1_data_last;ch1_frame_din {ch1_type,ch1_length};
endalways (posedge clk) beginch0_data_wren ch0_data_vld;ch0_data_din {ch0_data_last,ch0_data}; ch1_data_wren ch1_data_vld;ch1_data_din {ch1_data_last,ch1_data};
end/*--------------------------------------------------*\busy信号
\*--------------------------------------------------*/
always (posedge clk) beginif (reset) ch0_busy 0;else if (cur_status CH0_SEND send_data_last) ch0_busy 0;else if (cur_status CH0_SEND ~ch0_frame_rdempty)ch0_busy 1;
endalways (posedge clk) beginif (reset) ch1_busy 0;else if (cur_status CH1_SEND send_data_last) ch1_busy 0;else if (cur_status CH1_SEND ~ch1_frame_rdempty)ch1_busy 1;
end/*--------------------------------------------------*\状态机设计
\*--------------------------------------------------*/
always (posedge clk) beginif (reset) cur_status IDLE;else cur_status nxt_status;
endalways (*) beginif (reset) beginnxt_status IDLE; endelse begincase(cur_status)IDLE : beginnxt_status CH0_SEND;endCH0_SEND : beginif (~ch0_busy ch0_frame_rdempty)nxt_status CH1_SEND;else if (send_data_last)nxt_status CH1_SEND;else nxt_status cur_status;endCH1_SEND : beginif (~ch1_busy ch1_frame_rdempty)nxt_status CH0_SEND;else if (send_data_last)nxt_status CH0_SEND;else nxt_status cur_status;enddefault : nxt_status IDLE;endcase end
endalways (posedge clk) beginif (reset) beginsend_type 0;send_length 0;send_data_vld 0;send_data_last 0;send_data 0;endelse begincase(cur_status)IDLE : beginsend_type 0;send_length 0;send_data_vld 0;send_data_last 0;send_data 0;endCH0_SEND : beginif (ch0_frame_rden) beginsend_type ch0_frame_dout[31:16];send_length ch0_frame_dout[15:0];endelse beginsend_type send_type;send_length send_length;endif (ch0_data_rden) beginsend_data_vld 1b1;send_data_last ch0_data_dout[8];send_data ch0_data_dout[7:0];endelse beginsend_data_vld 0;send_data_last 0;send_data 0;endendCH1_SEND : beginif (ch1_frame_rden) beginsend_type ch1_frame_dout[31:16];send_length ch1_frame_dout[15:0];endelse beginsend_type send_type;send_length send_length;endif (ch1_data_rden) beginsend_data_vld 1b1;send_data_last ch1_data_dout[8];send_data ch1_data_dout[7:0];endelse beginsend_data_vld 0;send_data_last 0;send_data 0;end enddefault : ;endcaseend
end/*--------------------------------------------------*\FIFO读使能设计
\*--------------------------------------------------*/
always (posedge clk) beginif (reset) ch0_frame_rden 0;else if (cur_status CH0_SEND ~ch0_frame_rdempty ~ch0_busy) ch0_frame_rden 1b1;else ch0_frame_rden 0;
endalways (posedge clk) beginif (reset) ch1_frame_rden 0;else if (cur_status CH1_SEND ~ch1_frame_rdempty ~ch1_busy) ch1_frame_rden 1b1;else ch1_frame_rden 0;
endalways (posedge clk) beginif (reset) ch0_data_rden 0;else if (ch0_data_rden ch0_data_dout[8]) ch0_data_rden 0;else if (ch0_frame_rden)ch0_data_rden 1b1;else ch0_data_rden ch0_data_rden;
endalways (posedge clk) beginif (reset) ch1_data_rden 0;else if (ch1_data_rden ch1_data_dout[8]) ch1_data_rden 0;else if (ch1_frame_rden)ch1_data_rden 1b1;else ch1_data_rden ch1_data_rden;
end/*--------------------------------------------------*\调试信号
\*--------------------------------------------------*/
always (posedge clk) beginif (reset) ch0_frame_fifo_err 0;else if (ch0_frame_wren ch0_frame_wrfull) ch0_frame_fifo_err 1;else ch0_frame_fifo_err ch0_frame_fifo_err;
endalways (posedge clk) beginif (reset) ch1_frame_fifo_err 0;else if (ch1_frame_wren ch1_frame_wrfull) ch1_frame_fifo_err 1;else ch1_frame_fifo_err ch1_frame_fifo_err;
endalways (posedge clk) beginif (reset) ch0_data_fifo_err 0;else if (ch0_data_wren ch0_data_wrfull) ch0_data_fifo_err 1;else ch0_data_fifo_err ch0_data_fifo_err;
endalways (posedge clk) beginif (reset) ch1_data_fifo_err 0;else if (ch1_data_wren ch1_data_wrfull) ch1_data_fifo_err 1;else ch1_data_fifo_err ch1_data_fifo_err;
end/*--------------------------------------------------*\例化
\*--------------------------------------------------*/
fifo_w9xd2048 ch0_data_fifo (.clk (clk), // input wire clk.srst (reset), // input wire srst.din (ch0_data_din), // input wire [8 : 0] din.wr_en (ch0_data_wren), // input wire wr_en.rd_en (ch0_data_rden), // input wire rd_en.dout (ch0_data_dout), // output wire [8 : 0] dout.full (ch0_data_wrfull), // output wire full.empty (ch0_data_rdempty), // output wire empty.data_count(ch0_data_count) // output wire [11 : 0] data_count
);fifo_w9xd2048 ch1_data_fifo (.clk (clk), // input wire clk.srst (reset), // input wire srst.din (ch1_data_din), // input wire [8 : 0] din.wr_en (ch1_data_wren), // input wire wr_en.rd_en (ch1_data_rden), // input wire rd_en.dout (ch1_data_dout), // output wire [8 : 0] dout.full (ch1_data_wrfull), // output wire full.empty (ch1_data_rdempty), // output wire empty.data_count(ch1_data_count) // output wire [11 : 0] data_count
);fifo_w32xd16 ch0_frame_fifo (.clk (clk), // input wire clk.srst (reset), // input wire srst.din (ch0_frame_din), // input wire [31 : 0] din.wr_en (ch0_frame_wren), // input wire wr_en.rd_en (ch0_frame_rden), // input wire rd_en.dout (ch0_frame_dout), // output wire [31 : 0] dout.full (ch0_frame_wrfull), // output wire full.empty (ch0_frame_rdempty), // output wire empty.data_count(ch0_frame_count) // output wire [4 : 0] data_count
);fifo_w32xd16 ch1_frame_fifo (.clk (clk), // input wire clk.srst (reset), // input wire srst.din (ch1_frame_din), // input wire [31 : 0] din.wr_en (ch1_frame_wren), // input wire wr_en.rd_en (ch1_frame_rden), // input wire rd_en.dout (ch1_frame_dout), // output wire [31 : 0] dout.full (ch1_frame_wrfull), // output wire full.empty (ch1_frame_rdempty), // output wire empty.data_count(ch1_frame_count) // output wire [4 : 0] data_count
);endmodule编写测试
timescale 1ns / 1psmodule tb();parameter CH0_LENGTH 256 ;parameter CH0_PERIOD 300 ; parameter CH1_LENGTH 256 ;parameter CH1_PERIOD 300 ;reg clk;reg reset;wire ch0_data_vld;wire ch0_data_last;wire [7:0] ch0_data;wire ch1_data_vld;wire ch1_data_last;wire [7:0] ch1_data;wire [15:0] send_type;wire [15:0] send_length;wire send_data_vld;wire send_data_last;wire [7:0] send_data ;initial beginclk 0;forever #(10) clk ~clk;endinitial beginreset 1;#(2000) reset 0;enddata_generate #(.LENGTH(CH0_LENGTH),.PERIOD(CH0_PERIOD)) data_generate_ch0 (.clk (clk),.reset (reset),.send_data_vld (ch0_data_vld),.send_data_last (ch0_data_last),.send_data (ch0_data));data_generate #(.LENGTH(CH1_LENGTH),.PERIOD(CH1_PERIOD)) data_generate_ch1 (.clk (clk),.reset (reset),.send_data_vld (ch1_data_vld),.send_data_last (ch1_data_last),.send_data (ch1_data));mux2_arbit mux2_arbit(.clk (clk),.reset (reset),.ch0_type (16h0001),.ch0_length (CH0_LENGTH),.ch0_data_vld (ch0_data_vld),.ch0_data_last (ch0_data_last),.ch0_data (ch0_data),.ch1_type (16h0002),.ch1_length (CH1_LENGTH),.ch1_data_vld (ch1_data_vld),.ch1_data_last (ch1_data_last),.ch1_data (ch1_data),.send_type (send_type),.send_length (send_length),.send_data_vld (send_data_vld),.send_data_last (send_data_last),.send_data (send_data));endmodule仿真波形
