How do I buffer a signal in XST as I feel it is getting overloaded. if I write Signal1 <= Signal; XST automatically optimizes it. Please help. Naimesh
XST Question
Started by ●November 7, 2004
Reply by ●November 8, 20042004-11-08
"Naimesh" <naimesh.thakkar@gmail.com> wrote in message news:1099884025.786270.61150@f14g2000cwb.googlegroups.com...> How do I buffer a signal in XST as I feel it is getting overloaded. > if I write > Signal1 <= Signal; > XST automatically optimizes it.if the signal is a clock signal you can instantiate a BUFG or multiple BUFGs to optain load manual load balancing Antti
Reply by ●November 8, 20042004-11-08
"Naimesh" <naimesh.thakkar@gmail.com> writes:>How do I buffer a signal in XST as I feel it is getting overloaded. >if I write >Signal1 <= Signal; >XST automatically optimizes it.You can add "-max_fanout 50" (or whatever fanout you want) to the .xst-configfile or edit the appropriate GUI-form.... That setting is global, but it should be possible to pass it as an signal attribute. -- Georg Acher, acher@in.tum.de http://wwwbode.in.tum.de/~acher "Oh no, not again !" The bowl of petunias
Reply by ●November 8, 20042004-11-08
On Mon, 08 Nov 2004 12:02:41 +0000, Georg Acher wrote:> "Naimesh" <naimesh.thakkar@gmail.com> writes: >>How do I buffer a signal in XST as I feel it is getting overloaded. >>if I write >>Signal1 <= Signal; >>XST automatically optimizes it. > > You can add "-max_fanout 50" (or whatever fanout you want) to the .xst-configfile > or edit the appropriate GUI-form.... That setting is global, but it should be > possible to pass it as an signal attribute.Look at the constraints guide, you can set max fanout for a specific signal or you can do it globally.
Reply by ●December 25, 20042004-12-25
We are using a 20 input (each 8 bit wide) coregen instantiated MUX operating at 160 MHz on a Vitex-E device. When placed and routed in ISE6.2i, we get that the timing-error that the mux select lines are having fanout problem. We tried duplicating the net source, but still the problem persists. Any Help please.