Need help with niosII core and onchip_mem

Hello guys!!

i need some help with my new niosII core. i tried to program a Ep2C20 with a niosII softcore. but it doesn't work till now.

my system configurations are:

- nios II core (nios II/e, reset vector: onchip_mem offset: 0x00,

exception vector : onchip_mem offset: 0x20,

no caches or memory interfaces,

no advanced features,

jtag debug module level 1,

no custom instructions

)

- out_pio (7-bit output port only)

- onchip_mem (ram-writable,

block type auto,

initialize memory content is checked,

data width : 32-bit, memory size : 4096 bytes

read latency : slave s1

)

if i try to prgram compiled core with the led demo of the nios ide nothing happens. but if i try to program my nios II development kit Ep2C35 everythimng looks fine.

what's the reason for this?? can anybody help me please?? what are the minimum requirement of a niosII core with onchip_mem core?? what's the ideal size of the onchip_mem??

thank you very much for help!!!