A
Allan Herriman
Guest
Hi,
I have V6 design which instantiates a number (6) idelayctrl primitives.
(They're not really different, it just turned out easier to structure the
code that way.)
Recently, a co-worker modified the design so that the module hierarchy is
slightly different, in that the module containing four of the idelayctrl
primitives is now one level deeper in the hierarchy. I am reasonably
sure that there were no functional changes to the code, just a change in
hierarchy.
With the change, XST silently removes the four idelayctrl from the
design. In the resource utilization (sic) part of the synthesis report
file, it says it uses 2 idelayctrl. If I revert the changes in the
source files and run XST again, it reports 6 idelayctrl.
Can someone please give me a hint as to what's going on? I suspect there
is a rule that XST follows regarding merging of idelayctrl primitives,
but I can't find anything about it in any documentation.
TIA,
Allan
I have V6 design which instantiates a number (6) idelayctrl primitives.
(They're not really different, it just turned out easier to structure the
code that way.)
Recently, a co-worker modified the design so that the module hierarchy is
slightly different, in that the module containing four of the idelayctrl
primitives is now one level deeper in the hierarchy. I am reasonably
sure that there were no functional changes to the code, just a change in
hierarchy.
With the change, XST silently removes the four idelayctrl from the
design. In the resource utilization (sic) part of the synthesis report
file, it says it uses 2 idelayctrl. If I revert the changes in the
source files and run XST again, it reports 6 idelayctrl.
Can someone please give me a hint as to what's going on? I suspect there
is a rule that XST follows regarding merging of idelayctrl primitives,
but I can't find anything about it in any documentation.
TIA,
Allan