Problem with FPGA and SRAM

[Altera_Forum]

I have a problem with my FPGA board.MY board mainly contains EP1C6T144I7N(FPGA),  

IS61LV12816L (external sram ) and EPCS16. Application program can run in SRAM successfully online .If I download the sof file and the elf file into EPCS16 and turn on the power again,the application program can't run successfully in external sram . If the application program dosen't run in external sram but in on-chip ram of FPGA,the application program can run successfully after I download the sof file and the elf file into EPCS16.What should I pay attention to when use SRAM? Could anyone do me a favor?

[Altera_Forum]

Hi, 

 Can you elaborate the problems in some more details? Are you able to download the program and run from On-chip RAM and not from SRAM through IDE? Some more elaborated details would help analyzing the problem.  Regards, BD

[Altera_Forum]

A guess is that you may not be initializing your initialized variables after power on. If things work correctly whenever you download, but not when you boot out of flash, there is an application note on Altera's Nios II literature page that may help you which describes boot scenarios, called "AN 458: Alteranative Nios II Boot Methods", at http://www.altera.com/literature/an/an458.pdf