Xilinx AXI VIP使用教程
Xilinx提供了用于验证AXI相关设计的AXI VIP（AXI Verification IP），它可以对自己设计的AXI接口模块进行全方位的验证（如使用VIP的Master、Passthrough、Slave三种模式对自己写的AXI接口进行仿真验证），提前规避和发现一些不满足AXI总线规范的设计问题。本文以Master AXI VIP为例，介绍其使用方法。
1. 创建block design
此处默认block design的名字为design_1。
2. 添加相关ip
- 输入axi vip，添加axi vip ip核
2. INTERFACE MODE选择MASTER。
3. 添加AXI BRAM Controller和Block Memory Generator IP。同时将AXI BRAM Controller的接口数减少为1个。
4. 按下图所示进行连线
5. 为时钟和复位信号创建输入端口。
6. 分配地址空间, Validate Design, Generate Output Products, 然后Create HDL Wrapper.
- 创建testbench，语言类型选择system verilog。代码如下：
`timescale 1ns / 1ps
import axi_vip_pkg::*;
import design_1_axi_vip_0_0_pkg::*;
module tb_top();
bit clk;
bit aresetn;
//used in API and parital randomization for transaction generation and data read back from driver
axi_transaction wr_transaction; // Write transaction
axi_transaction rd_transaction; // Read transaction
xil_axi_uint mtestWID; // Write ID
xil_axi_ulong mtestWADDR; // Write ADDR
xil_axi_len_t mtestWBurstLength; // Write Burst Length
xil_axi_size_t mtestWDataSize; // Write SIZE
xil_axi_burst_t mtestWBurstType; // Write Burst Type
xil_axi_uint mtestRID; // Read ID
xil_axi_ulong mtestRADDR; // Read ADDR
xil_axi_len_t mtestRBurstLength; // Read Burst Length
xil_axi_size_t mtestRDataSize; // Read SIZE
xil_axi_burst_t mtestRBurstType; // Read Burst Type
xil_axi_lock_t mtestLOCK; // LOCK value for WRITE/READ_BURST transaction
xil_axi_cache_t mtestCacheType = 3; // Cache Type value for WRITE/READ_BURST transaction
xil_axi_prot_t mtestProtectionType = 3'b000; // Protection Type value for WRITE/READ_BURST transaction
xil_axi_region_t mtestRegion = 4'b000; // Region value for WRITE/READ_BURST transaction
xil_axi_qos_t mtestQOS = 4'b000; // QOS value for WRITE/READ_BURST transaction
xil_axi_data_beat dbeat; // Data beat value for WRITE/READ_BURST transaction
xil_axi_user_beat usrbeat; // User beat value for WRITE/READ_BURST transaction
xil_axi_data_beat [255:0] mtestWUSER; // Wuser value for WRITE/READ_BURST transaction
xil_axi_data_beat mtestAWUSER = 'h0; // Awuser value for WRITE/READ_BURST transaction
xil_axi_data_beat mtestARUSER = 0; // Aruser value for WRITE/READ_BURST transaction
xil_axi_data_beat [255:0] mtestRUSER; // Ruser value for WRITE/READ_BURST transaction
xil_axi_uint mtestBUSER = 0; // Buser value for WRITE/READ_BURST transaction
xil_axi_resp_t mtestBresp; // Bresp value for WRITE/READ_BURST transaction
xil_axi_resp_t[255:0] mtestRresp; // Rresp value for WRITE/READ_BURST transaction
bit [63:0] mtestWData; // Write Data
bit[8*4096-1:0] Wdatablock; // Write data block
xil_axi_data_beat Wdatabeat[]; // Write data beats
bit [63:0] mtestRData; // Read Data
bit[8*4096-1:0] Rdatablock; // Read data block
xil_axi_data_beat Rdatabeat[]; // Read data beats
initial begin
aresetn = 1'b0;
clk = 1'b0;
#100ns;
aresetn = 1'b1;
end
always #10 clk <= ~clk;
design_1 u_dut(
.aclk (clk ),
.aresetn (aresetn )
);
design_1_axi_vip_0_0_mst_t mst_agent;
initial begin
mst_agent = new("master vip agent",u_dut.axi_vip_0.inst.IF);
mst_agent.start_master(); // mst_agent start to run
mtestWID = $urandom_range(0,(1<<(0)-1));
mtestWADDR = 'hc000_1000;//$urandom_range(0,(1<<(32)-1));
mtestWBurstLength = 0;
mtestWDataSize = xil_axi_size_t'(xil_clog2((32)/8));
mtestWBurstType = XIL_AXI_BURST_TYPE_INCR;
mtestWData = 'h12345678;//$urandom();
$display("mtestWDataSize = %d", mtestWDataSize);
//single write transaction filled in user inputs through API
single_write_transaction_api("single write with api",
.id(mtestWID),
.addr(mtestWADDR),
.len(mtestWBurstLength),
.size(mtestWDataSize),
.burst(mtestWBurstType),
.wuser(mtestWUSER),
.awuser(mtestAWUSER),
.data(mtestWData)
);
mtestRID = $urandom_range(0,(1<<(0)-1));
mtestRADDR = mtestWADDR;
mtestRBurstLength = 0;
mtestRDataSize = xil_axi_size_t'(xil_clog2((32)/8));
mtestRBurstType = XIL_AXI_BURST_TYPE_INCR;
$display("mtestRDataSize = %d", mtestRDataSize);
//single read transaction filled in user inputs through API
single_read_transaction_api("single read with api",
.id(mtestRID),
.addr(mtestRADDR),
.len(mtestRBurstLength),
.size(mtestRDataSize),
.burst(mtestRBurstType)
);
end
task automatic single_write_transaction_api (
input string name ="single_write",
input xil_axi_uint id =0,
input xil_axi_ulong addr =0,
input xil_axi_len_t len =0,
input xil_axi_size_t size =xil_axi_size_t'(xil_clog2((32)/8)),
input xil_axi_burst_t burst =XIL_AXI_BURST_TYPE_INCR,
input xil_axi_lock_t lock = XIL_AXI_ALOCK_NOLOCK,
input xil_axi_cache_t cache =3,
input xil_axi_prot_t prot =0,
input xil_axi_region_t region =0,
input xil_axi_qos_t qos =0,
input xil_axi_data_beat [255:0] wuser =0,
input xil_axi_data_beat awuser =0,
input bit [63:0] data =0
);
axi_transaction wr_trans;
$display("single_write_transaction_api size = %d", size);
wr_trans = mst_agent.wr_driver.create_transaction(name);
wr_trans.set_write_cmd(addr,burst,id,len,size);
wr_trans.set_prot(prot);
wr_trans.set_lock(lock);
wr_trans.set_cache(cache);
wr_trans.set_region(region);
wr_trans.set_qos(qos);
wr_trans.set_data_block(data);
mst_agent.wr_driver.send(wr_trans);
endtask : single_write_transaction_api
task automatic single_read_transaction_api (
input string name ="single_read",
input xil_axi_uint id =0,
input xil_axi_ulong addr =0,
input xil_axi_len_t len =0,
input xil_axi_size_t size =xil_axi_size_t'(xil_clog2((32)/8)),
input xil_axi_burst_t burst =XIL_AXI_BURST_TYPE_INCR,
input xil_axi_lock_t lock =XIL_AXI_ALOCK_NOLOCK ,
input xil_axi_cache_t cache =3,
input xil_axi_prot_t prot =0,
input xil_axi_region_t region =0,
input xil_axi_qos_t qos =0,
input xil_axi_data_beat aruser =0
);
axi_transaction rd_trans;
$display("single_read_transaction_api size = %d", size);
rd_trans = mst_agent.rd_driver.create_transaction(name);
rd_trans.set_read_cmd(addr,burst,id,len,size);
rd_trans.set_prot(prot);
rd_trans.set_lock(lock);
rd_trans.set_cache(cache);
rd_trans.set_region(region);
rd_trans.set_qos(qos);
mst_agent.rd_driver.send(rd_trans);
endtask : single_read_transaction_api
endmodule
其中，import design_1_axi_vip_0_0_pkg::*;和design_1_axi_vip_0_0_mst_t mst_agent;语句中的design_1为block_design名称。需根据实际情况修改。
design_1 u_dut(
.aclk (clk ),
.aresetn (aresetn )
);
是对顶层设计模块的例化，模块名以及接口信号名称也需要根据实际情况修改，使之对应。
8. 运行仿真，并观察波形。
