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Altera_Forum's avatar
Altera_Forum
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12 years ago

Custom FIFO read in Nios IDE

I created a custom fifo in sopc builder and i am trying to read data from fifo. However, i got no idea about how to manipulate it .Is it right if i make a pointer which points at the base address of ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

If you have a data cache then this won't work. On the first loop iteration the CPU will read from your FIFO, but for the next iterations it will just read the value again from the cache instead of accessing your FIFO. Something like this would be better (not tested)

#include <sys/alt_cache.h>
alt_16 *my_fifo = alt_remap_uncached((void*)CUSTOM_FIFO_IP_BASE,sizeof(alt_16));
for(counter = 0 ;counter < 255 ;counter++)
{
   write_buffer = *my_fifo ; 
}