Forum Discussion
Altera_Forum
Honored Contributor
19 years agoOk, I solved the problem.
I used ldw and stw to read a word from the flash memory and store it into the ram memory. But I need to use the stwio instruction to move the data to ram. This is because I need to bypass the cache. So the boot loader is working now http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/cool.gif But there is something I don't understand. The boot loader runs a memory test, a very simple one. It stores a word on the base address of the SDRAM and load it back from that address: stw r_mem_test_val, 0(r_ddr_sdram_base_ptr) ldw r_mem_test_ret_val, 0(r_ddr_sdram_base_ptr) cmpeq r_compare_resul, r_mem_test_ret_val, r_mem_test_val But when I change these instructions to stwio and ldwio, the test fails and I don't understand why. Could somebody give me an explanation for this? thanks Regards Ronald