<pb_type name="io" capacity="8" area="0"> | |
<input name="outpad" num_pins="1"/> | |
<output name="inpad" num_pins="1"/> | |
<clock name="clock" num_pins="1"/> | |
<!-- IOs can operate as either inputs or outputs. | |
Delays below come from Ian Kuon. They are small, so they should be interpreted as | |
the delays to and from registers in the I/O (and generally I/Os are registered | |
today and that is when you timing analyze them. | |
--> | |
<mode name="inpad"> | |
<pb_type name="inpad" blif_model=".input" num_pb="1"> | |
<output name="inpad" num_pins="1"/> | |
</pb_type> | |
<interconnect> | |
<direct name="inpad" input="inpad.inpad" output="io.inpad"> | |
<delay_constant max="4.243e-11" in_port="inpad.inpad" out_port="io.inpad"/> | |
</direct> | |
</interconnect> | |
</mode> | |
<mode name="outpad"> | |
<pb_type name="outpad" blif_model=".output" num_pb="1"> | |
<input name="outpad" num_pins="1"/> | |
</pb_type> | |
<interconnect> | |
<direct name="outpad" input="io.outpad" output="outpad.outpad"> | |
<delay_constant max="1.394e-11" in_port="io.outpad" out_port="outpad.outpad"/> | |
</direct> | |
</interconnect> | |
</mode> | |
<!-- Every input pin is driven by 15% of the tracks in a channel, every output pin is driven by 10% of the tracks in a channel --> | |
<fc in_type="frac" in_val="0.15" out_type="frac" out_val="0.10"/> | |
<!-- IOs go on the periphery of the FPGA, for consistency, | |
make it physically equivalent on all sides so that only one definition of I/Os is needed. | |
If I do not make a physically equivalent definition, then I need to define 4 different I/Os, one for each side of the FPGA | |
--> | |
<pinlocations pattern="custom"> | |
<loc side="left">io.outpad io.inpad io.clock</loc> | |
<loc side="top">io.outpad io.inpad io.clock</loc> | |
<loc side="right">io.outpad io.inpad io.clock</loc> | |
<loc side="bottom">io.outpad io.inpad io.clock</loc> | |
</pinlocations> | |
<!-- Place I/Os on the sides of the FPGA --> | |
<gridlocations> | |
<loc type="perimeter" priority="10"/> | |
</gridlocations> | |
<power method="ignore"/> | |
</pb_type> |