These is something wrong about DDR reading and writing
When I used the DDR sdram( MT46V16M16)as the palce in which the program run. The nios console showed that the verification was failed. So I changed to run the program in the onchip ram, and then writed and read the DDR. From the address of 0x2f6 to the address of 0x305, the data read was not the data written, the data between the address of 0x6f6 to 7f5, 0xaf6 to 0xb05, 0xef6 to 0xf05 were wrong, too. The data writen is its address, howere, the data read is 0. When I change to run the program in another board, it have the same thing. Thanks very much for your reply!!