SDRAM Read and write address control

@daixiwen

i am writing to sdram. i dont use the PLL core. i only use the DE board external interface core to provide the clock needed. do i have to use the PLL? but i dont know how to configure it.

here is a part of my code to write to sdram

sdram_index=0;

for(a=0;a<64;a++)

{

IOWR_ALTERA_AVALON_PIO_DATA(SDRAM_0_BASE+sdram_index,jpeg_data.mtrx_Y1[a]);

jpeg_data.sdram_index+=2;

}

and then i read it with command

IORD_ALTERA_AVALON_PIO_DATA(SDRAM_0_BASE+offset);

the value of jpeg_data.mtrx_Y1[0] is -23 which is supposed to be written in offset 0, but when i read the offset 0, i dont get -23.