kaisopos
Newbie level 4
hi all,
I get a significantly different slack in dc and primetime. Since I am a newbie, I am not sure if this is reasonable or I did something wrong.
the details:
I synthesized my design in dc and I fed the synthesized netlist to primetime (with exactly the same constraints file and the same .lib file). So, dc could meet timing for frequencies up to 500 MHz (2ns clock): for 500MHz I got 0 slack, while for 550MHz I got a -0.11ns slack).
However, primetime indicates that for a 2ns clock I have a 0.34ns slack, which implies that I could run my design at 1/(2-0.34)ns = 600MHz. I am aware that dc does very basic timing analysis, while primetime is pretty accurate, but does this account for such a huge (17%) slack diff, implying that I could run at 100MHz more? What do you think? Did I mess up something or is this reasonable?
thanks a lot!
-Kostas
I get a significantly different slack in dc and primetime. Since I am a newbie, I am not sure if this is reasonable or I did something wrong.
the details:
I synthesized my design in dc and I fed the synthesized netlist to primetime (with exactly the same constraints file and the same .lib file). So, dc could meet timing for frequencies up to 500 MHz (2ns clock): for 500MHz I got 0 slack, while for 550MHz I got a -0.11ns slack).
However, primetime indicates that for a 2ns clock I have a 0.34ns slack, which implies that I could run my design at 1/(2-0.34)ns = 600MHz. I am aware that dc does very basic timing analysis, while primetime is pretty accurate, but does this account for such a huge (17%) slack diff, implying that I could run at 100MHz more? What do you think? Did I mess up something or is this reasonable?
thanks a lot!
-Kostas