Clustering greatly helps the placer to identify and pack together
specific cells at the same site (e.g. LUT+FF), or cells that are chained through
dedicated interconnections (e.g. CARRY CHAINS)
Signed-off-by: Alessandro Comodi <acomodi@antmicro.com>
This is required for LUTRAM support, as the upper address bits of
RAMD64E etc are missing for shallower primitives.
Signed-off-by: gatecat <gatecat@ds0.me>
The previous logic tied LUT input pins to VCC if a wire was unplacable.
This missed a case where the net was present to the input of the LUT,
but a wire was still not legal. This case is now prevented by tying the
output of the LUT to an unused net.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
This resulted in valid site routing solutions being missed. Underlying
bug was an off-by-one error when unwinding a failed solution.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
- Finishes implementation of SiteArch::nameOfPip and SiteArch::nameOfWire
- Adds "explain_bel_status", which should be an exhaustive diagnostic
of the status of a BEL placement.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
If get_net_type was called before the driver was placed, it could return
the wrong value.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
For now just implements some inspection capabilities, and the site
router (for now) avoids inverted paths.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
The new site router should be robust to most situations, and isn't
significantly slower with the use of caching.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
Fixes:
- Only use map constant pins during routing, and not during placement.
- Unmapped cell ports have no BEL pins.
- Fix SiteRouter congestion not taking into account initial expansion.
- Fix psuedo-site pip output.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
This site router likely cannot handle the full problem space. It may
need to be replaced with a more generalize approach as testing
continues.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
