256MByte boundary not supported ?

Thanks for that explanaition. i thought that it had to do with some addressing limitations but i must have overseen this when reading the altera online documents this morning again.

as this is a limitation by the opcodes i guess that this will be forever.

i thought of using uclinux and spent a lot of sdram but i cannot garantee that the memory will only be used for data.

and as i have to attach an epcs controler as well as the jtag stuff the instruction space for the system is less than 256mbyte. as i can not tell the sdram controller to implement 3 chip selects of 64mb (to have 192mb) i can only choose betwen 128 and 256mbyte but that is not implementable with epcs

so the design is limited to 128mbyte sdram (for instruction and data) with one sdram controller

that is a lot of memory but i thought of what would be possible in the future. 640k was enough for DOS and 640MByte is not much nowadays for quartus :-)

again thanks for your comments.

regards

michael schmitt