How to use Slave FIFO 2x, 3x, 4x?

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable

I have built a FPGA project to test the slave FIFO, I found that when FIFO size is set to 512 or 1024, the FF flag wil go active when 512 or 1024 words are written into the FIFO, it seems there is no relationship between 2x, 3x, or 4x of FIFO depth, is it the truth? why?

0 Likes
2 Replies
AjayB_76
Moderator
Moderator
Moderator
100 sign-ins 10 questions asked 5 questions asked

I presume you are talking about FX2LP. This is the expected behavior and flag behaves in this way itself. 

   
        
0 Likes
Anonymous
Not applicable

Yes, it's CY7C68013A.  I also found that when EP2 was set to be size=512, buffering=2x, first I use console tool to read fifo until empty, then trigger to write 512 word into fifo, again to read fifo using console tool, I can read back 1024 word until console tool can't read. I guess this is not the expected behavior, but why? What's wrong?

0 Likes