Fpga Configuration Interface And Experimental Development Evaluation Board Design Based On Usb2.0 And Implementation

With rapid developments of system on chip (SOC), the reconfigurable SOC based on programmable logic devices (PLD), including complex programmable logic device (CPLD) and field programmable gate array (FPGA), which can support in-system programmability (ISP) become more and more popular. This trend also set higher standard to download cables than ever before, which are used to program PLDs.This article researches how to design and accomplish universal serial bus (USB) download interface circuit and FPGA development board based on IEEE std.1149.1 specification. Based on deep comprehension of IEEE std.1149.1 specification and USB principle, the author contraposed USB-Blaster, a kind of USB download interface circuit which is special used in Altera.Co and analysised its inter communication system then actualized the total software and hardware design of USB download interface circuit and FPGA development board, accomplished the configuration function of Altera serials PLDs and the function of FPGA development board.Those design excised already always need to design a software terminal to control the communication between download interface circuit and object programmable device. But it's not convenient for usage, and what's more, it may beget compatible problem in different operation system. The download interface circuit discussed in this article has already be proved can be directly used in QuartusII with higher compatible capability. But its application is limited because that it's price is relatively higher and PLD manufactures keep a secret to protect their intellectual Property. And this situation also set more difficulty to researchers to design it by themselves.Compared with traditional download cable based on PC's parallel port, the download circuit and FPGA development board based on PC's USB port has many advantages, such as higher download speed, hot-plugging, slim, portable, convenient in installing,and it owns the advantages that the other configuration interface circuits, such as the function of SignalTapII embedded logic analyzer and debugging NiosII embedded CPU. According to the price, the USB download interface circuit and FPGA development board has good ability of competition.