對(duì)FPGA進(jìn)行上板調(diào)試時(shí)，使用最多的是SignalTap，但SignalTap主要用來抓取信號(hào)時(shí)序，當(dāng)需要發(fā)送信號(hào)到FPGA時(shí)，Jtag Master可以發(fā)揮很好的作用，可以通過Jtag Master對(duì)FPGA進(jìn)行讀寫測試，使用tcl腳本控制Jtag Master可以完成復(fù)雜的測試功能。使用jtag master進(jìn)行調(diào)試時(shí)分為如下步驟：

• 將JTAG to Avalon Master Bridge Intel FPGA IP加入代碼
• 根據(jù)Avalon-MM總線時(shí)序編寫測試代碼
• 編寫tcl腳本
• 在System Console上運(yùn)行tcl腳本進(jìn)行調(diào)試

Jtag Master
在邏輯代碼中加入JTAG to Avalon Master Bridge Intel FPGA IP ，IP路徑如下。

Avalon-MM總線時(shí)序
jtag_master模塊例化到fpga代碼中，使用Verilog根據(jù)Avalon-MM時(shí)序圖編寫讀寫代碼。master_read有效時(shí)將數(shù)據(jù)發(fā)送到master_readdata。master_write有效時(shí)，將master_writedata數(shù)據(jù)寫入FPGA。

jtag_master u0 (
.clk_clk (_connected_to_clk_clk_),
.clk_reset_reset (_connected_to_clk_reset_reset_),
.master_reset_reset (_connected_to_master_reset_reset_),
.master_address (_connected_to_master_address_),
.master_readdata (_connected_to_master_readdata_),
.master_read (_connected_to_master_read_),
.master_write (_connected_to_master_write_),
.master_writedata (_connected_to_master_writedata_),
.master_waitrequest (_connected_to_master_waitrequest_),
.master_readdatavalid (_connected_to_master_readdatavalid_),
.master_byteenable (_connected_to_master_byteenable_)
);

編寫TCL腳本

global claimed_path_jtag
#啟動(dòng)jtag master服務(wù)
proc start_jtag {} {
set service_type "master"
set jtag_path [lindex [get_service_paths $service_type] 0]
puts $jtag_path
set ::claimed_path_jtag [claim_service $service_type $jtag_path mylib]
}
# 下載函數(shù)
proc config {sof_file} {
set device_index 0
set device [lindex [get_service_paths device] $device_index]
puts "download..."
device_download_sof $device $sof_file
}
#關(guān)閉jtag master服務(wù)
proc end_jtag {} {
close_service master $::claimed_path_jtag
}
#寫函數(shù)
proc jtag_write {addr data} {
master_write_32 $::claimed_path_jtag $addr $data
}
#讀函數(shù)
proc jtag_read {addr} {
set result [master_read_32 $::claimed_path_jtag $addr 1]
return $result
}
#測試讀寫
proc test { } {
#地址0中寫入1
jtag_write 0x0 0x1
#讀取地址0
jtag_read 0x0
}

上電測試
打開System Console

運(yùn)行如下指令
source jtag.tcl //tcl 腳本
config output_files/test.sof //下載文件
start_jtag //打開jatg master服務(wù)
test //測試讀寫函數(shù)
end_jtag //關(guān)閉jatg master服務(wù)

審核編輯：符乾江