homer2k1
Newbie level 5
astro create placement
I'm trying to lay out a design with two large modules connected by some simple glue logic. I want the modules to be laid out physically as two separate bodies on the chip. I know the placed-and-routed area of each individual module, and I'm using that for two plan groups (see below).
My current flow:
Design Compiler (synthesis: gate-level netlist)
Astro (initial floorplan: outer chip dimensions, power/ground rings)
Physical Compiler (placement: *)
Astro again (clock tree and routing)
The problem seems to be with * in PC above. I'm trying the following to create a "relative placement group" for each module (rt1 and rt2):
create_rp_group group1 -x_offset 100 -y_offset 100 -rows 1 -columns 1
add_to_rp_group group1 -leaf rt1 -column 0 -row 0
create_rp_group group2 -x_offset 100 -y_offset 400 -rows 1 -columns 1
add_to_rp_group group2 -leaf rt2 -column 0 -row 0
create_placement
[write milkyway, def, etc.]
No errors, but when I save the Milkyway cell and try to open it in Astro again, it says there are thousands of cells outside the design boundary. If I cut out the create/add_rp_group commands and just use the auto placer, I have no problems in CTS and routing.
Am I missing anything? Thanks in advance for your help.
I'm trying to lay out a design with two large modules connected by some simple glue logic. I want the modules to be laid out physically as two separate bodies on the chip. I know the placed-and-routed area of each individual module, and I'm using that for two plan groups (see below).
My current flow:
Design Compiler (synthesis: gate-level netlist)
Astro (initial floorplan: outer chip dimensions, power/ground rings)
Physical Compiler (placement: *)
Astro again (clock tree and routing)
The problem seems to be with * in PC above. I'm trying the following to create a "relative placement group" for each module (rt1 and rt2):
create_rp_group group1 -x_offset 100 -y_offset 100 -rows 1 -columns 1
add_to_rp_group group1 -leaf rt1 -column 0 -row 0
create_rp_group group2 -x_offset 100 -y_offset 400 -rows 1 -columns 1
add_to_rp_group group2 -leaf rt2 -column 0 -row 0
create_placement
[write milkyway, def, etc.]
No errors, but when I save the Milkyway cell and try to open it in Astro again, it says there are thousands of cells outside the design boundary. If I cut out the create/add_rp_group commands and just use the auto placer, I have no problems in CTS and routing.
Am I missing anything? Thanks in advance for your help.
