Each DSP block contains two slices, and each slice contains multiple
MULT18X18D and ALU54B units. Each unit configures each register to use
any of CLK0/1/2/3, CE0/1/2/3, and RST0/1/2/3 ports, and the ports are
connected per unit (so for example, two MULTs in the same block could
connect their CLK0s to different external signals). However, the
hardware only has one actual port per block, so it's required that
all CLK0 signals within a block are the same.
Because the packer is in general allowed to combine two unrelated units
into one block, it may end up combining units that use different signals
for the same port, which would eventually have caused a router failure.
This commit adds validity checks which ensure only unique signals are
used per block, and adds remapping so that conflicting signals are
automatically reassigned when possible and required.
This makes predictDelay be based on an arbitrary belpin pair rather
than a arc of a net based on cell placement. This way 'what-if'
decisions can be evaluated without actually changing placement;
potentially useful for parallel placement.
A new helper predictArcDelay behaves like the old predictDelay to
minimise the impact on existing passes; only arches need be updated.
Signed-off-by: gatecat <gatecat@ds0.me>
"nextpnr.h" is no longer the god header. Important improvements:
- Functions in log.h can be used without including
BaseCtx/Arch/Context. This means that log_X functions can be called
without included "nextpnr.h"
- NPNR_ASSERT can be used without including "nextpnr.h" by including
"nextpnr_assertions.h". This allows NPNR_ASSERT to be used safely in
any header file.
- Types defined in "archdefs.h" are now available without including
BaseCtx/Arch/Context. This means that utility classes that will be
used inside of BaseCtx/Arch/Context can be defined safely in a
self-contained header.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
This replaces the arch-specific DelayInfo structure with new DelayPair
(min/max only) and DelayQuad (min/max for both rise and fall) structures
that form part of common code.
This further reduces the amount of arch-specific code; and also provides
useful data structures for timing analysis which will need to delay
with pairs/quads of delays as it is improved.
While there may be a small performance cost to arches that didn't
separate the rise/fall cases (arches that aren't currently separating
the min/max cases just need to be fixed...) in DelayInfo, my expectation
is that inlining will mean this doesn't make much difference.
Signed-off-by: gatecat <gatecat@ds0.me>
This Arch API dates from when we were first working out how to
implement placement validity checking, and in practice is little used by
the core parts of placer1/HeAP and the Arch implementation involves a
lot of duplication with isBelLocationValid.
In the short term; placement validity checking is better served by the
combination of checkBelAvail and isValidBelForCellType before placement;
followed by isBelLocationValid after placement (potentially after
moving/swapping multiple cells).
Longer term, removing this API makes things a bit cleaner for a new
validity checking API.
Signed-off-by: gatecat <gatecat@ds0.me>
This makes the Arch API clearer and also allows a base implementation of
functions to reduce the amount of complexity to get a basic Arch up and
running.
Currently this only implements these for functions that don't return a
range. Range-returning functions will require more work in order due to
the current 'duck typing' approach (probably a struct that contains the
range types combined with templating.)
Signed-off-by: D. Shah <dave@ds0.me>
This makes the difference clearer between the general arch API that
everyone must implement; and helper functions specific to one arch.
Signed-off-by: D. Shah <dave@ds0.me>
This is a complete implementation of IdStringList for ECP5; excluding
the GUI (which you will have to disable for it to build).
Signed-off-by: D. Shah <dave@ds0.me>
This uses the new IdStringList API to store bel names for the ECP5. Note
that other arches and the GUI do not yet build with this
proof-of-concept patch.
getBelByName still uses the old implementation and could be more
efficiently implemented with further development.
Signed-off-by: D. Shah <dave@ds0.me>
This replaces RelPtrs and a separate length field with a Rust-style
slice containing both a pointer and a length; with bounds checking
always enforced.
Thus iterating over these structures is both cleaner and safer.
Signed-off-by: D. Shah <dave@ds0.me>
These operations are meaningless for a data structure that references
another structure relative to its location.
Signed-off-by: David Shah <dave@ds0.me>
It has not actually been implemented in any router for over 2.5 years and causes nothing more than confusion. It can always be added back if it forms part of a future solution; possibly as part of a more general database structure rethink.
Signed-off-by: David Shah <dave@ds0.me>
