How can I set a false path within a macro?
Tool: OpenSTA
Subcategory: Usage question
Conversation
oharboe
I want to set a false path for two pins on a macro, but not at the macro's level, but rather at the containing macros level.
and thought it was supported. Though when I read https://github.com/The-OpenROAD-Project/OpenSTA/blob/3275a304e17092895b7d7721148edc7dc67ba3aa/search/Sta.cc#L2080, it looks like I can only use the ports of the macro for the constraints.sdc file as -to and -from.
No changes are intended for mock-array w.r.t. this, I'm only using mock-array to illustrate what I'm trying to find the syntax for:
>>> set_false_path -from [get_pins ces_6_6/io_ins_right*] -to [get_pins ces_6_6/io_outs_right*]
[WARNING STA-0018] 'ces_6_6/io_ins_right[0]' is not a valid start point.
[WARNING STA-0018] 'ces_6_6/io_ins_right[10]' is not a valid start point.
[WARNING STA-0018] 'ces_6_6/io_ins_right[11]' is not a valid start point.
[WARNING STA-0018] 'ces_6_6/io_ins_right[12]' is not a valid start point.
vijayank88
@oharboe I got this from OpenSTA user guide:
from_list A list of clocks, instances, ports or pins.
through_list A list of instances, pins or nets.
to_list A list of clocks, instances, ports or pins.
So as per this you can provide pins also.
The **set_false_path** command disables timing along a path from, through and to a group of design objects.
Objects in **from_list** can be clocks, register/latch instances, or register/latch clock pins. The -rise_from
and -fall_from keywords restrict the false paths to a specific clock edge.
Objects in **through_list** can be nets, instances, instance pins, or hierarchical pins,. The -rise_through
and -fall_through keywords restrict the false paths to a specific path edge that traverses through the
object.
Objects in **to_list** can be clocks, register/latch instances, or register/latch clock pins. The -rise_to and -
fall_to keywords restrict the false paths to a specific transition at the path end.
maliberty
You probably need to use -through as those points are not the beginning or end of a timing path.
maliberty
I suspect you want
set_false_path -through [get_pins ces_6_6/io_ins_right*] -through [get_pins ces_6_6/io_outs_right*]