第五步是编写数据处理模块
generator与driver两者之间的通信属于异步通信机制才能实现通信。generator发送给agent数据没有时序性，需要driver发送数据DUT的时候偶，进行一定的时序处理。
`ifndef DRIVER_SV `define DRIVER_SV class friver int tr_num; transaction tr; mailbox agt2drv_mbx=new(); virtual ahb_slv_if slv_if; logic [31:0] hwdata_ld; extern function new(int tr_num,virtual ahb_slv_if slv_if, mailbox agt2drv_mbx); extern function build(); extern task run(); endclass function driver::new(int tr_num,virtual ahb_slv_if slv_if, mailbox agt2drv_mbx); this.tr_num = tr_num; this.agt2drv_mbx = agt2drv_mbx; this.slv_if = slv_if; endfunction function driver::build(); endfunction task driver::run(); @(posedge slv_if.hresetn); @slv_if.drv_cb; @slv_if.drv_cb; repeat@(tr_num) tr = new(); agt2drv_mbx.get(tr); wait@(slv_if.hready.hresp); slv_if.drv_cb.hsel <= hsel ; slv_if.drv_cb.haddr <= haddr ; slv_if.drv_cb.hwrite <= hwrite; slv_if.drv_cb.htrans <= htrans ; slv_if.drv_cb.hsize <= hsize ; slv_if.drv_cb.hready <= hready ; hwdata_ld <= hrdata; @slv_if.drv_cb; slv_if.drv_cb.hwdata <= hwdata_ld; repeat@(10) begin @slv_if.drv_cb; end endtask `endif 第六步是编写采样模块
monitor模块的主要功能是处理采集的数据，使地址阶段与数据阶段同步，然后发送到scoreboard里面去。这里面有个较为关键的地方就是，haddr需要先复制haddr_ld，然后再通过haddr_ld传递给tr，hwdata可以直接传递给tr。这是根据AHB根据其特点，一个操作需要两个周期来完成。第一个周期是地址周期，第二个周期是数据周期。时间协议规定的地址和控制信号在数据前的时钟周期interface过来的信号，一定要按AHB协议来做，但是环境内没有时序，tr包含所有内容的数据包没有时间序列。所以如果把相应的证据和命令放在一个包里，就相当于同步调整，放在同一个周期。因为地址要和数据一样——拍摄，所以比数据晚——拍摄。
`ifndef MONITOR_SV `define MONITOR_SV class monitor; mailbox mon2scb_mbx = new(); transaction tr; virtaul ahb_slv_if slv_if int tr_num; logic [31:0] haddr_ld; logic hwrite_ld; logic [1:0] htrans_ld; logic [1:0] hsize_ld; logic hsel_ld; extern function new(mailbox mon2scb_mbx,virtaul ahb_slv_if slv_if,int tr_num); extern function build(); extern task run(); endclass function monitor::new(mailbox mon2scb_mbx,virtaul ahb_slv_if slv_if,int tr_num); this.mon2scb_mbx = mon2scb_mbx; this.slv_if = slv_if; this.tr_num = tr_num; endfunction function monitor::build(); endfunction task monitor::run(); @(posedge slv_if.hresetn); @slv_if.mon_cb; @slv_if.mon_cb; repeat(tr_num)begin tr = new(); haddr_ld <= slv_if.mon_cb.haddr; htrans_ld <= slv_if.mon_cb.htrans; hwrite_ld <= slv_if.mon_cb.hwrite; hsize_ld <= slv_if.mon_cb.hsize; hsel_ld <= slv_if.mon_cb.hsel; @slv_if.mon_cb; tr.haddr = haddr_ld; tr.htrans = htrans_ld; tr.hwrite = hwrite_ld; tr.hsize = hsize_ld; tr.hsel = hsel_ld; tr.hwdata = slv_if.mon_cb.hwdata; tr.hrdata = slv_if.mon_cb.hrdata; mon2scb_mbx.put(tr); end repeat(10) begin @slv_if.mon_cb; end endtask `endif 第七步是编写自动比较模块
scoreboard部分会把agent发送的数据和monitor比较发送的数据。关键是构建一个由寄存器组成的存储器，其数据位宽为32bit，深度为2^地址宽度为14，因为我们是gloden模型跟RTL不同的是，我们没有分裂bank,只要数据能写进去，就没有物理实现，只有逻辑功能才能实现。tr.haddr[ADDR_WIDTH-1:2]本列为/4操作，系统地址转换为物理地址。
`ifndef SCOREBOARD_SV `define SCOREBOARD_SV class scoreboard; int tr_num; mailbox agt2scb_mbx = new(); mailbox mon2scb_mbx = new(); transaction tr = new(); //定义golden_model参数 parameter ADDR_WIDTH = 16; parameter SRAM_ADDR_WIDTH =ADDR_WIDTH -2; parameter SRAM_DEPTH = 1<<(SRAM_ADDR_WIDTH); logic [31:0]sram_gld[SRAM_DEPTH ]; int err_cnt = 0; extern function new(int tr_num,mailbox agt2scb_mbx,mailbox mon2scb_mbx ); extern function build(); extern task check(); extern task run(); endclass function scoreboard::new(int tr_num,mailbox agt2scb_mbx,mailbox mon2scb_mbx ); this.agt2scb_mbx = agt2scb_mbx ; this.mon2scb_mbx = mon2scb_mbx ; this.tr_num= tr_num; endfunction function scoreboard::build(); endfunction task scoreboard:: check(); repeat(tr_num)begin mon2scb_mbx.get(tr) if(tr.hsel && tr.htrans[]) begin if(tr.hwrite) begin case({tr.hsize[1:0],tr.haddr[1:0]}) 4'b00_00:sram_gld[tr.haddr[ADDR_WIDTH-1:2][7:0] = tr.hwdata[7:0]; 4'b00_01:sram_gld[tr.haddr[ADDR_WIDTH-1:2]][15:0] = tr.hwdata[15:0];
4'b00_10:sram_gld[tr.haddr[ADDR_WIDTH-1:2]][23:16] =tr.hwdata[23:16];
4'b00_11:sram_gld[tr.haddr[ADDR_WIDTH-1:2]][31:24] =tr.hwdata[31:24];
4'b00_00:sram_gld[tr.haddr[ADDR_WIDTH-1:2]][15:0] = tr.hwdata[15:0];
4'b01_01:sram_gld[tr.haddr[ADDR_WIDTH-1:2]][31:16] =tr.hwdata[31:16];
4'b10_00:sram_gld[tr.haddr[ADDR_WIDTH-1:2]]= tr.hwdata[31:0];
default:begin
sram_gld[tr.haddr[ADDR_WIDTH-1:2]]= 32'hx;
$display("@%ot:ERROR::MISMATCH*",$time ,tr.hsize,tr.haddr[1:0]);
err_cnt++;
end
endcase
end
else begin
if(tr.hdata != sram_gld[tr.haddr[ADDR_WIDTH-1:2]])begin
$display("@ot:ERROR::tr.hdata != sram_gld[tr.haddr[ADDR_WIDTH-1:2]]",$time ,tr.hdata,sram_gld[tr.haddr[ADDR_WIDTH-1:2]],tr.haddr);
err_cnt++;
end
end
end
end
endtask
task scoreboard::run();
check();
if(err_cnt == 0)beign
$display("**********************************************");
$display("**********************************************");
$display("*****************TEST PASS*******************");
$display("**********************************************");
$display("**********************************************");
end
else begin
$display("**********************************************");
$display("**********************************************");
$display("*****************TEST FAILD*******************",err_cnt);
$display("**********************************************");
$display("**********************************************");
end
endtask
`endif第八步、编写环境部分
环境部分通过定义公共邮箱，把各个部分的组件连接起来，实现数据在不同组件中进行传输。new和build都是起连接的作用，只不过就是new的时候跟把env上面一层的相关的接口信号连接到env内部的成员里面来；build阶段就是把new阶段连接的成员信息又连接到drv里面来。environment中所有的数值都是从testcase中得到的
`ifndef ENVIRONMENT_SV
`define ENVIRONMENT_SV
class environment;
generator gen;
agent agt;
driver drv;
scoreboard scb;
monitor mon;
int tr_num;
mailbox gen2agt_mbx = new();
mailbox agt2drv_mbx = new();
mailbox agt2scb_mbx = new();
mailbox mon2scb_mbx = new();
virtual ahb_slv_if slv_if;
extern function new(int tr_num, virtual ahb_slv_if slv_if);
extern function build();
extern task run();
endclass
function environment::new(int tr_num, virtual ahb_slv_if slv_if);
this.tr_num = tr_num ;
this.slv_if = slv_if ;
endfunction
function environment::build();
gen = new(gen2agt_mbx ,tr_num);
agt = new(gen2agt_mbx ,agt2drv_mbx ,agt2scb_mbx,tr_num);
drv = new(agt2drv_mbx,slv_if,tr_num);
scb = new(agt2scb_mbx ,mon2scb_mbx ,tr_num);
mon = new(mon2scb_mbx ,slv_if,tr_num);
endfunction
task environment::run();
fork
gen.run();
agt.run();
drv.run();
mon.run();
scb.run();
join
endtask
`endif第九步、编写测试用例
测试模块采用program块进行编写，这样可以利用该模块隐式的执行$finish来结束仿真，同时定义覆盖组还可以收集功能覆盖率
`ifndef AHB_SRAM_TEST_SV
`difine AHB_SRAM_TEST_SV
program automatic ahb_sram_test(ahb_slv_if slv_if);
int tr_num= 20;
int tc_num =0;
int rnd_seed;
covergroup ahb_slv_cg();
coverpoint slv_if.hsel{ bins hsel = {0,1};
}
coverpoint slv_if.hwrite{ bins write= {0};
bins read = {1};
}
coverpoint slv_if.hsize{ bins hsize_8= {2'b00};
bins hsize_16= {2'b01};
bins hsize_31= {2'b10};
}
coverpoint slv_if.haddr{ bins haddr_0 = {[32'h0:32'h0000_1FFF]};
bins haddr_1 = {[32'h0000_2000:32'h0000_3FFF]};
bins haddr_2 = {[32'h0000_4000:32'h0000_5FFF]};
bins haddr_3 = {[32'h0000_6000:32'h0000_7FFF]};
bins haddr_4 = {[32'h0000_8000:32'h0000_9FFF]};
bins haddr_5 = {[32'h0000_A000:32'h0000_BFFF]};
bins haddr_6 = {[32'h0000_C000:32'h0000_DFFF]};
bins haddr_7 = {[32'h0000_E000:32'h0000_FFFF]};
}
coverpoint slv_if.hwdata{ { bins hwdata_0byte={[32'h0:32'hFF]};
bins hwdata_1byte={[32'h100:32'hFF_00]};
bins hwdata_2byte={[32'h1_0000:32'hFF_0000]};
bins hwdata_3byte={[32'h100_0000:32'hFF00_0000]};
}
coverpoint slv_if.hrdata{ bins hrdata_0byte={[32'h0:32'hFF]};
bins hrdata_1byte={[32'h100:32'hFF_00]};
bins hrdata_2byte={[32'h1_0000:32'hFF_0000]};
bins hrdata_3byte={[32'h100_0000:32'hFF00_0000]};
}
endgroup
class tc_base;
int tr_num;
encironment ahb_env;
virtual ahb_slv_if slv_if;
ahb_slv_cg slv_cg=new();
extern function new(virtual ahb_slv_if slv_if,int tr_num);
extern function build();
extern virtual task run();
endclass
function tc_base::new(virtual ahb_slv_if slv_if,int tr_num);
this.slv_if = slv_if;
this.tr_num = tr_num;
endfunctiom
function tc_base::build();
ahb_env = new(this.slv_if ,tr_num);
ahb_env.build();
endfunction
task tc_base::run();
fork
ahb_env.run();
begin
@(posedge slv_if.hclk);
@(posedge slv_if.hresetn);
@(posedge slv_if.hclk);
repeat@(tr_num) begin
@(posedge slv_if.hclk);
slv_cg.sample(); 每一次发包，都对其功能覆盖率进行收集
end
end
jion
endtask
/*-------------------------------------------------------------------------------------*/
//测试用例
/*-------------------------------------------------------------------------------------*/
class tc000 extends tc_base;
extern function new(virtual ahb_slv_if slv_if,int tr_num);
extern virtual task run();
endclass
function tc000::new(virtual ahb_slv_if slv_if,int tr_num);
super.new(slv_if,tr_num);
endfunction
task tc000::run()
fork
super.run()
begin
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data32(i*4,i);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data32(i*4);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data16(i*2,i);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data16(i*2);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data8(i,i);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data8(i);
end
end
jion
endtask
class tc001 extends tc_base;
extern function new(virtual ahb_slave_if slv_if, int tr_num);
extern virtual task run();
endclass
function tc001::new(virtual ahb_slave_if slv_if, int tr_num);
super.new(slv_if,tr_num);
endfunction
task tc001::run();
fork
super.run();
begin
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data32(32'h0000_FFFC-i*4,32'h5A5A_5A5A);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data32(32'h0000_FFFC-i*4);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data16(32'h0000_FFFC-i*2,32'h0000_5A5A);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data16(32'h0000_FFFC-i*2);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data8(32'h0000_FFFC-i,32'h0000_005A);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data8(32'h0000_FFFC-i);
end
end
join
endtask
class tc002 extends tc_base;
extern function new(virtual ahb_slave_if slv_if, int tr_num);
extern virtual task run();
endclass
function tc002::new(virtual ahb_slave_if slv_if, int tr_num);
super.new(slv_if,tr_num);
endfunction
task tc002::run();
fork
super.run();
begin
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data32_random(i*4);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data32(i*4);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data16_random(i*2);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data16(i*2);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.write_data8_random(i);
end
for(int i=0;i<(tr_num/6);i++)begin
#1;
ahb_env.gen.read_data8(i);
end
end
join
endtask
class tc003 extends tc_base;
extern function new(virtual ahb_slave_if slv_if, int tr_num);
extern virtual task run();
endclass
function tc003::new(virtual ahb_slave_if slv_if, int tr_num);
super.new(slv_if,tr_num);
endfunction
task tc003::run();
fork
super.run();
begin
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.write_data8(32'h0000_FFFC-i,i);
#1;
ahb_env.gen.no_op();
end
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.read_data8(32'h0000_FFFC-i);
#1;
ahb_env.gen.no_op();
end
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.write_data16(32'h0000_FFFC-i*2,i);
#1;
ahb_env.gen.no_op();
end
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.read_data16(32'h0000_FFFC-i*2);
#1;
ahb_env.gen.no_op();
end
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.write_data32(32'h0000_FFFC-i*4,i);
#1;
ahb_env.gen.no_op();
end
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.read_data32(32'h0000_FFFC-i*4);
#1;
ahb_env.gen.no_op();
end
end
join
endtask
class tc004 extends tc_base;
extern function new(virtual ahb_slave_if slv_if, int tr_num);
extern virtual task run();
endclass
function tc004::new(virtual ahb_slave_if slv_if, int tr_num);
super.new(slv_if,tr_num);
endfunction
task tc004::run();
fork
super.run();
begin
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.write_data8_random(i);
#1;
ahb_env.gen.no_op();
#1;
ahb_env.gen.read_data8(i);
#1;
ahb_env.gen.no_op();
end
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.write_data16_random(i*2);
#1;
ahb_env.gen.no_op();
#1;
ahb_env.gen.read_data16(i*2);
#1;
ahb_env.gen.no_op();
end
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.write_data32_random(i*4);
#1;
ahb_env.gen.no_op();
#1;
ahb_env.gen.read_data32(i*4);
#1;
ahb_env.gen.no_op();
end
end
join
endtask
class tc005 extends tc_base;
extern function new(virtual ahb_slave_if slv_if, int tr_num);
extern virtual task run();
endclass
function tc005::new(virtual ahb_slave_if slv_if, int tr_num);
super.new(slv_if,tr_num);
endfunction
task tc005::run();
fork
super.run();
begin
for(int i=0;i<(tr_num/2);i++)begin
#1;
ahb_env.gen.write_data32(i*4,100+i);
end
for(int i=0;i<(tr_num/12);i++)begin
#1;
ahb_env.gen.read_data32(i*4);
end
end
join
endtask
class tc006 extends tc_base;
extern function new(virtual ahb_slave_if slv_if, int tr_num);
extern virtual task run();
endclass
function tc006::new(virtual ahb_slave_if slv_if, int tr_num);
super.new(slv_if,tr_num);
endfunction
task tc006::run();
fork
super.run();
begin
for(int i=0;i<(tr_num/8);i++)begin
#1;
ahb_env.gen.write_data32(i*4, 32'h0000_0000);
end
for(int i=0;i<(tr_num/8);i++)begin
#1;
ahb_env.gen.read_data32(i*4);
end
for(int i=0;i<(tr_num/8);i++)begin
#1;
ahb_env.gen.write_data32(i*4, 32'hFFFF_FFFF);
end
for(int i=0;i<(tr_num/8);i++)begin
#1;
ahb_env.gen.read_data32(i*4);
end
for(int i=0;i<(tr_num/8);i++)begin
#1;
ahb_env.gen.write_data32(i*4, 32'h5555_5555);
end
for(int i=0;i<(tr_num/8);i++)begin
#1;
ahb_env.gen.read_data32(i*4);
end
for(int i=0;i<(tr_num/8);i++)begin
#1;
ahb_env.gen.write_data32(i*4, 32'hAAAA_AAAA);
end
for(int i=0;i<(tr_num/8);i++)begin
#1;
ahb_env.gen.read_data32(i*4);
end
end
join
endtask
tc000 tc0;
tc001 tc1;
tc002 tc2;
tc003 tc3;
tc004 tc4;
tc005 tc5;
tc006 tc6;
initial begin
$vcdpluson(); //生成波形文件
if(!$vcdpluson$plusargs("tc_num=%d,tc_num")) begin
end
else begin
$display("@%ot::tc_num is : %d",$time,tc_num);
end
end
tc0 = new(slv_if,6000); //传递接口和发包数量
tc1 = new(slv_if,600); //定向用例
tc2 = new(slv_if,6000);
tc3 = new(slv_if,1200);
tc4 = new(slv_if,6000);
tc5 = new(slv_if,3000);
tc6 = new(slv_if,3000); //随即用例
tc7 = new(slv_if,32'h0002_0000); //遍历整个SRAM空间，0,1,5，a
if(tc_num == 0)begin
tc0.build();
tc0.run();
end
else if(tc_num == 1)begin
tc1.build();
tc1.run();
end
else if(tc_num == 2)begin
tc2.build();
tc2.run();
end
else if(tc_num == 3)begin
tc3.build();
tc3.run();
end
else if(tc_num == 4)begin
tc4.build();
tc4.run();
end
else if(tc_num == 5)begin
tc5.build();
tc5.run();
end
else if(tc_num == 6)begin
tc6.build();
tc6.run();
end
else begin
$display("@%0t : ERROR tc_num(%0d) does not exist",$time,tc_num);
end
end
endprogram
`endif 主要部分是覆盖组的的定义，用于收集功能覆盖率；其次是测试用例的编写，主要是八个部分：
测试用例0：从较低地址开始写+读，包含8、16、32bit的数据；
测试用例1：从较高地址开始写+读，包含8、16、32bit的数据，32和16位数据读写固定了数据大小；
测试用例2：随机写读数据，按32、16、8的顺序；
测试用例3：从较高地址开始写+读，包含8、16、32bit的数据；
测试用例4：随机写读数据，中间插入无效操作 no_op（）；
测试用例5：较低地址写读32位数据；
测试用例6：随机写读数据；
测试用例7：写读数据，地址遍历每个空间，数据固定为四种；
第十步、编写顶层连接文件top
通过interface来建立测试用例和DUT之间的连接。
module ahb_sramc_svtb_top();
bit hclk;
bit sram_clk;
bit hresetn;
ahb_slv_if ahb_sramc_if(hclk);
ahb_sram_test test(ahb_sramc_if);
sramc_top u_sramc_top(
.hclk (hclk),
.sram_clk (sram_clk),
.hresetn (ahb_sramc_if.hresetn),
.hsel (ahb_sramc_if.hsel),
.hwrite (ahb_sramc_if.hwrite),
.htrans (ahb_sramc_if.htrans),
.hsize (ahb_sramc_if.hsize),
.hready (ahb_sramc_if.hready),
.hburst (3'b0),
.haddr (ahb_sramc_if.haddr),
.hwdata (ahb_sramc_if.hwdata),
.hrdata (ahb_sramc_if.hrdata),
.dft_en (1'b0),
.bist_en (1'b0),
.hready_resp (ahb_sramc_if.hready_resp),
.hresp (ahb_sramc_if.hresp),
.bist_done ( ),
.bist_fail ( )
);
initial begin
forever #10 hclk = ~ hclk;
end
always @(*) sram_clk = ~hclk;
initial begin
hresetn = 1;
#1 hresetn = 0;
#10 hresetn = 1;
end
assign ahb_sramc_if.hresetn = hresetn; //开始的时候先进行复位操作
endmodule
代码参考： AHB—SRAMC基于SV的Testbench之二（driver、monitor、scoreboard、environment）_SD.ZHAI的博客-CSDN博客