Instead of just marking all clock domains as asynchronous set the
appropriate constraints for each CDC path.
For single-bit synchronizers use set_false_path to not constraint the path
at at all.
For multi-bit synchronizers as used for gray counters use set_max_delay with
the source clock period domain to make sure that the signal skew will not
exceed one clock period. Otherwise one bit might overtake another and the
synchronizer no longer works correctly.
For multi-bit synchronizers implemented with hold registers use
set_max_delay with the target clock period to make sure that the skew does
not get to large, otherwise we might violate setup and hold time.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
This is unused and unneeded. The AXI interconnect will make sure that a
peripheral only gets requests that are meant for it, there is no need to
check the address in the peripheral itself.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Lars-Peter Clausen
Rejeesh Kutty
Adrian Costina