这里主要是针对EP3C系列FPGA的Nios程序固化到EPCS中的方法做简要说明。硬件SOPC1、要固化程序到EPCS，在SOPC Builder中首先需要添加EPCS_Controller核，此外，CPU的reset vector设置为EPCS_Controller,Exception Vector一般设置为SDRAM即可。2、生成该nios_cpu。对于EP3C系列的FPGA来说，在生成cpu后，会出现与EPCS_Controller相关的4根引线(如图)，

这在之前的EP2C等早期系列的FPGA中是没有的，因为系统已经默认完成了相应的设置，而EP3C是需要自己来对这些引脚设置的，

这一点尤为要注意，下面就来具体说明一下。这4根信号线分别为(EP3C10F256)：EPCS_DATA0   ->  H2ASDO                 ->  C1nCS0,(Flash_nCE)  ->  D2DCLK                ->  H1在对这4根引线进行引脚分配的时候，要在Device中将这些双功能引脚功能都设置为regular I/O Pin，否则会出现错误：比如:Error：Can't place multiple pins assigned to pin location PIN_H2                        ......对这些引脚做完这些设置后，即可进行编译、下载了(引脚分配如下图)。

另外，在使用Quartus II 10.0高版本编译Cyclone IV器件的时候，可能在Device->Dual Purpose里面的DCLK等引脚没有

USE AS Regular I/O选项，用户就无法给DCLK这些引脚指定Pin Assignment。这时的解决办法是：打开工程的.qsf文件，加上以下几句(若存在对这4个引脚的其它类似配置信息时，先删除)：set_global_assignment -name RESERVED_FLASH_NCE_AFTER_CONFIGURATION "USE AS REGULAR IO"set_global_assignment -name RESERVED_DATA0_AFTER_CONFIGURATION "USE AS REGULAR IO"set_global_assignment -name RESERVED_DATA1_AFTER_CONFIGURATION "USE AS REGULAR IO"set_global_assignment -name RESERVED_DCLK_AFTER_CONFIGURATION "USE AS REGULAR IO"保存并编译，就可以正确读写EPCS了。软件Nios1、在nios中建立相应工程，并编译。2、编译完成之后，打开FLASH Programmer。勾上Program FPGA configuration data into hardware-image region of flash memory(将FPGA的配置文件写入Flash(EPCS))，并设置对应的.sof文件Hardware Image设置为Custom，Memory设置为EPCS_Controller，offset为0x0，不勾选Program a file into flash memory(可将二进制文件写入Flash)。完成后如图所示：

以上所有设置完成后，Apply，然后Program Flash即可。烧写成功后，会有如下信息：

#!/bin/sh## This file was automatically generated by the Nios II IDE Flash Programmer.## It will be overwritten when the flash programmer options change.#

cd D:/MySoftwares/QuartusII/Mywork/sopc_project/led_test/software/led_test/Debug

# Creating .flash file for the FPGA configuration"$SOPC_KIT_NIOS2/bin/sof2flash" --epcs --input="D:/MySoftwares/QuartusII/Mywork/sopc_project/led_test/led_test.sof" --output="led_test.flash" Info: *******************************************************************Info: Running Quartus II Convert_programming_fileInfo: Command: quartus_cpf --no_banner --convert --device=EPCS128 --option=led_test.opt D:/MySoftwares/QuartusII/Mywork/sopc_project/led_test/led_test.sof led_test.pofInfo: Quartus II Convert_programming_file was successful. 0 errors, 0 warnings    Info: Peak virtual memory: 70 megabytes    Info: Processing ended: Wed Mar 30 12:34:48 2011    Info: Elapsed time: 00:00:02    Info: Total CPU time (on all processors): 00:00:02Info: *******************************************************************Info: Running Quartus II Convert_programming_fileInfo: Command: quartus_cpf --no_banner --convert led_test.pof led_test.rpdInfo: Quartus II Convert_programming_file was successful. 0 errors, 0 warnings    Info: Peak virtual memory: 68 megabytes    Info: Processing ended: Wed Mar 30 12:34:51 2011    Info: Elapsed time: 00:00:03    Info: Total CPU time (on all processors): 00:00:02

# Programming flash with the FPGA configuration"$SOPC_KIT_NIOS2/bin/nios2-flash-programmer" --epcs --base=0x01001800 --sidp=0x01002018 --id=1794073991 --timestamp=1301451768 --instance=0 "led_test.flash"Using cable "USB-Blaster [USB-0]", device 1, instance 0x00Resetting and pausing target processor: OKReading System ID at address 0x01002018: verified

: Checksumming existing contents

00000000      : Verifying existing contents

00010000      : Verifying existing contents

00020000      : Verifying existing contents

00000000      : Reading existing contents

00010000      : Reading existing contents

00020000      : Reading existing contents

Checksummed/read 54kB in 1.4s

00000000 ( 0%): Erasing

00010000 (33%): Erasing

00020000 (66%): Erasing

Erased 192kB in 1.9s (101.0kB/s)

00000000 ( 0%): Programming

00010000 (33%): Programming

00020000 (66%): Programming

Programmed 139KB +53KB in 3.3s (58.1KB/s)                  Did not attempt to verify device contentsLeaving target processor paused

# Creating .flash file for the project"$SOPC_KIT_NIOS2/bin/elf2flash" --epcs --after="led_test.flash" --input="led_test.elf" --output="epcs_controller.flash"

# Programming flash with the project"$SOPC_KIT_NIOS2/bin/nios2-flash-programmer" --epcs --base=0x01001800 --sidp=0x01002018 --id=1794073991 --timestamp=1301451768 --instance=0 "epcs_controller.flash"Using cable "USB-Blaster [USB-0]", device 1, instance 0x00Resetting and pausing target processor: OKReading System ID at address 0x01002018: verified

: Checksumming existing contents

00020000      : Verifying existing contents

00020000      : Reading existing contents

Checksummed/read 42kB in 1.1s

00020000 ( 0%): Erasing

Erased 64kB in 0.6s (106.6kB/s)

00020000 ( 0%): Programming

Programmed 23KB +41KB in 0.7s (91.4KB/s)                   Did not attempt to verify device contentsLeaving target processor paused

烧写完成，Reset或者断电重启，烧写在EPCS中的程序即开始运行了。