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Each architecture must implement the following types and APIs.
Architectures can either inherit from `ArchAPI<ArchRanges>`, which is a pure virtual description of the architecture API; or `BaseArch<ArchRanges>` which provides some default implementations described below.
`ArchRanges` is a `struct` of `using`s that allows arches to return custom range types. These ranges can be anything that has a `begin()` and `end()` method that return const forward iterators. This can be a `std::list<T>`, `std::vector<T>`, a (const) reference to those, or anything else that behaves in a similar way.
The contents of `ArchRanges` is as follows:
| Type | Range of |
|---------------------------|----------------------------------|
|`ArchArgsT` | N/A (struct of device params) |
|`AllBelsRangeT` | `BelId` |
|`TileBelsRangeT` | `BelId` |
|`BelAttrsRangeT` | std::pair<IdString, std::string> |
|`BelPinsRangeT` | `IdString` |
|`AllWiresRangeT` | `WireId` |
|`DownhillPipRangeT` | `PipId` |
|`UphillPipRangeT` | `PipId` |
|`WireBelPinRangeT` | `BelPin` |
|`AllPipsRangeT` | `PipId` |
|`PipAttrsRangeT` | std::pair<IdString, std::string> |
|`AllGroupsRangeT` | `GroupId` |
|`GroupBelsRangeT` | `BelId` |
|`GroupWiresRangeT` | `WireId` |
|`GroupPipsRangeT` | `PipId` |
|`GroupGroupsRangeT` | `GroupId` |
|`DecalGfxRangeT` | `GraphicElement` |
|`CellTypeRangeT` | `IdString` |
|`BelBucketRangeT` | `BelBucketRange` |
|`BucketBelRangeT` | `BelId` |
The functions that return a particular type are described below. Where a default function implementation is provided, `BaseArchRanges` (which `ArchRanges` can inherit from) will set the range type appropriately.
archdefs.h
==========
The architecture-specific `archdefs.h` must define the following types.
With the exception of `ArchNetInfo` and `ArchCellInfo`, the following types should be "lightweight" enough so that passing them by value is sensible.
### delay\_t
A scalar type that is used to represent delays. May be an integer or float type.
### DelayInfo
A struct representing the delay across a timing arc. Must provide a `+` operator for getting the combined delay of two arcs, and the following methods to access concrete timings:
```
delay_t minRaiseDelay() const { return delay; }
delay_t maxRaiseDelay() const { return delay; }
delay_t minFallDelay() const { return delay; }
delay_t maxFallDelay() const { return delay; }
delay_t minDelay() const { return delay; }
delay_t maxDelay() const { return delay; }
```
### BelId
A type representing a bel name. `BelId()` must construct a unique null-value. Must provide `==`, `!=`, and `<` operators and a specialization for `std::hash<BelId>`.
### WireId
A type representing a wire name. `WireId()` must construct a unique null-value. Must provide `==`, `!=`, and `<` operators and a specialization for `std::hash<WireId>`.
### PipId
A type representing a pip name. `PipId()` must construct a unique null-value. Must provide `==`, `!=`, and `<` operators and a specialization for `std::hash<PipId>`.
### BelBucketId
A type representing a bel bucket. `BelBucketId()` must construct a unique null-value. Must provide `==`, `!=`, and `<` operators and a specialization for `std::hash<BelBucketId>`.
### GroupId
A type representing a group name. `GroupId()` must construct a unique null-value. Must provide `==` and `!=` operators and a specialization for `std::hash<GroupId>`.
### DecalId
A type representing a reference to a graphical decal. `DecalId()` must construct a unique null-value. Must provide `==` and `!=` operators and a specialization for `std::hash<DecalId>`.
### ArchNetInfo
The global `NetInfo` type derives from this one. Can be used to add arch-specific data (caches of information derived from wire attributes, bound wires and pips, and other net state). Must be declared as empty struct if unused.
### ArchCellInfo
The global `CellInfo` type derives from this one. Can be used to add arch-specific data (caches of information derived from cell attributes and parameters, bound bel, and other cell state). Must be declared as empty struct if unused.
arch.h
======
Each architecture must provide their own implementation of the `Arch` struct in `arch.h`. `Arch` must derive from `BaseCtx` and must provide the following methods:
General Methods
---------------
### Arch(ArchArgs args)
Constructor. ArchArgs is a architecture-specific type (usually a struct also defined in `arch.h`).
### std::string getChipName() const
Return a user-friendly string representation of the ArchArgs that was used to construct this object.
### ArchArgs archArgs() const
Return the `ArchArgs` used to construct this object.
### IdString archArgsToId(ArchArgs args) const
Return an internal IdString representation of the ArchArgs that was used to construct this object.
*BaseArch default: returns empty IdString*
### int getGridDimX() const
Get grid X dimension. All bels and pips must have Y coordinates in the range `0 .. getGridDimX()-1` (inclusive).
### int getGridDimY() const
Get grid Y dimension. All bels and pips must have Y coordinates in the range `0 .. getGridDimY()-1` (inclusive).
### int getTileBelDimZ(int x, int y) const
Get Z dimension for the specified tile for bels. All bels with at specified X and Y coordinates must have a Z coordinate in the range `0 .. getTileDimZ(X,Y)-1` (inclusive).
### int getTilePipDimZ(int x, int y) const
Get Z dimension for the specified tile for pips. All pips with at specified X and Y coordinates must have a Z coordinate in the range `0 .. getTileDimZ(X,Y)-1` (inclusive).
*BaseArch default: returns 1*
### char getNameDelimiter() const
Returns a delimiter that can be used to build up bel, wire and pip names out of hierarchical components (such as tiles and sites) to avoid the high memory usage of storing full names for every object.
*BaseArch default: returns ' '*
Cell Methods
-----------
### CellTypeRangeT getCellTypes() const
Get list of cell types that this architecture accepts.
*BaseArch default: returns list derived from bel types set up by `init_cell_types()`*
Bel Methods
-----------
### BelId getBelByName(IdStringList name) const
Lookup a bel by its name, which is a list of IdStrings joined by `getNameDelimiter()`.
### IdStringList getBelName(BelId bel) const
Get the name for a bel. (Bel names must be unique.)
### Loc getBelLocation(BelId bel) const
Get the X/Y/Z location of a given bel. Each bel must have a unique X/Y/Z location.
### BelId getBelByLocation(Loc loc) const
Lookup a bel by its X/Y/Z location.
### TileBelsRangeT getBelsByTile(int x, int y) const
Return a list of all bels at the give X/Y location.
### bool getBelGlobalBuf(BelId bel) const
Returns true if the given bel is a global buffer. A global buffer does not "pull in" other cells it drives to be close to the location of the global buffer.
*BaseArch default: returns false*
### uint32\_t getBelChecksum(BelId bel) const
Return a (preferably unique) number that represents this bel. This is used in design state checksum calculations.
*BaseArch default: returns `std::hash` of `BelId` cast to `uint32_t`*
### void bindBel(BelId bel, CellInfo \*cell, PlaceStrength strength)
Bind a given bel to a given cell with the given strength.
This method must also update `cell->bel` and `cell->belStrength`.
*BaseArch default: binds using `base_bel2cell`*
### void unbindBel(BelId bel)
Unbind a bel.
This method must also update `CellInfo::bel` and `CellInfo::belStrength`.
*BaseArch default: unbinds using `base_bel2cell`*
### bool checkBelAvail(BelId bel) const
Returns true if the bel is available. A bel can be unavailable because it is bound, or because it is exclusive to some other resource that is bound.
*BaseArch default: returns `getBoundBelCell(bel) == nullptr`*
### CellInfo \*getBoundBelCell(BelId bel) const
Return the cell the given bel is bound to, or nullptr if the bel is not bound.
*BaseArch default: returns entry in `base_bel2cell`*
### CellInfo \*getConflictingBelCell(BelId bel) const
If the bel is unavailable, and unbinding a single cell would make it available, then this method must return that cell.
*BaseArch default: returns `getBoundBelCell(bel)`*
### AllBelsRangeT getBels() const
Return a list of all bels on the device.
### IdString getBelType(BelId bel) const
Return the type of a given bel.
### bool getBelHidden(BelId bel) const
Should this bel be hidden from utilities?
*BaseArch default: returns false*
### BelAttrsRangeT getBelAttrs(BelId bel) const
Return the attributes for that bel. Bel attributes are only informal. They are displayed by the GUI but are otherwise
unused. An implementation may simply return an empty range.
*BaseArch default: returns default-constructed range*
### WireId getBelPinWire(BelId bel, IdString pin) const
Return the wire connected to the given bel pin.
### PortType getBelPinType(BelId bel, IdString pin) const
Return the type (input/output/inout) of the given bel pin.
### BelPinsRangeT getBelPins(BelId bel) const
Return a list of all pins on that bel.
Wire Methods
------------
### WireId getWireByName(IdStringList name) const
Lookup a wire by its name, which is a list of IdStrings joined by `getNameDelimiter()`.
### IdStringList getWireName(WireId wire) const
Get the name for a wire. (Wire names must be unique.)
### IdString getWireType(WireId wire) const
Get the type of a wire. The wire type is purely informal and
isn't used by any of the core algorithms. Implementations may
simply return `IdString()`.
*BaseArch default: returns empty IdString*
### WireAttrsRangeT getWireAttrs(WireId wire) const
Return the attributes for that wire. Wire attributes are only informal. They are displayed by the GUI but are otherwise
unused. An implementation may simply return an empty range.
*BaseArch default: returns default-constructed range*
### uint32\_t getWireChecksum(WireId wire) const
Return a (preferably unique) number that represents this wire. This is used in design state checksum calculations.
*BaseArch default: returns `std::hash` of `WireId` cast to `uint32_t`*
### void bindWire(WireId wire, NetInfo \*net, PlaceStrength strength)
Bind a wire to a net. This method must be used when binding a wire that is driven by a bel pin. Use `binPip()`
when binding a wire that is driven by a pip.
This method must also update `net->wires`.
*BaseArch default: binds using `base_wire2net`*
### void unbindWire(WireId wire)
Unbind a wire. For wires that are driven by a pip, this will also unbind the driving pip.
This method must also update `NetInfo::wires`.
*BaseArch default: unbinds using `base_wire2net`*
### bool checkWireAvail(WireId wire) const
Return true if the wire is available, i.e. can be bound to a net.
*BaseArch default: returns `getBoundWireNet(wire) == nullptr`*
### NetInfo \*getBoundWireNet(WireId wire) const
Return the net a wire is bound to.
*BaseArch default: returns entry in `base_wire2net`*
### WireId getConflictingWireWire(WireId wire) const
If this returns a non-WireId(), then unbinding that wire
will make the given wire available.
*BaseArch default: returns `wire`*
### NetInfo \*getConflictingWireNet(WireId wire) const
If this returns a non-nullptr, then unbinding that entire net
will make the given wire available.
*BaseArch default: returns `getBoundWireNet(wire)`*
### DelayInfo getWireDelay(WireId wire) const
Get the delay for a wire.
### AllWiresRangeT getWires() const
Get a list of all wires on the device.
### WireBelPinRangeT getWireBelPins(WireId wire) const
Get a list of all bel pins attached to a given wire.
### ArcBounds getRouteBoundingBox(WireId src, WireId dst) const
Get the bounding box required to route an arc, assuming an uncongested
chip. There may be significant performance impacts if routing regularly
exceeds these bounds by more than a small margin; so an over-estimate
of the bounds is almost always better than an under-estimate.
Pip Methods
-----------
### PipId getPipByName(IdStringList name) const
Lookup a pip by its name, which is a list of IdStrings joined by `getNameDelimiter()`.
### IdStringList getPipName(PipId pip) const
Get the name for a pip. (Pip names must be unique.)
### IdString getPipType(PipId pip) const
Get the type of a pip. Pip types are purely informal and
implementations may simply return `IdString()`.
*BaseArch default: returns empty IdString*
### PipAttrsRangeT getPipAttrs(PipId pip) const
Return the attributes for that pip. Pip attributes are only informal. They are displayed by the GUI but are otherwise
unused. An implementation may simply return an empty range.
*BaseArch default: returns default-constructed range*
### Loc getPipLocation(PipId pip) const
Get the X/Y/Z location of a given pip. Pip locations do not need to be unique, and in most cases they aren't. So
for pips a X/Y/Z location refers to a group of pips, not an individual pip.
### uint32\_t getPipChecksum(PipId pip) const
Return a (preferably unique) number that represents this pip. This is used in design state checksum calculations.
*BaseArch default: returns `std::hash` of `WireId` cast to `uint32_t`*
### void bindPip(PipId pip, NetInfo \*net, PlaceStrength strength)
Bid a pip to a net. This also bind the destination wire of that pip.
This method must also update `net->wires`.
*BaseArch default: binds using `base_pip2net` and `base_wire2net`*
### void unbindPip(PipId pip)
Unbind a pip and the wire driven by that pip.
This method must also update `NetInfo::wires`.
*BaseArch default: unbinds using `base_pip2net` and `base_wire2net`*
### bool checkPipAvail(PipId pip) const
Returns true if the given pip is available to be bound to a net.
Users must also check if the pip destination wire is available
with `checkWireAvail(getPipDstWire(pip))` before binding the
pip to a net.
*BaseArch default: returns `getBoundPipNet(pip) == nullptr`*
### NetInfo \*getBoundPipNet(PipId pip) const
Return the net this pip is bound to.
*BaseArch default: returns entry in `base_pip2net`*
### WireId getConflictingPipWire(PipId pip) const
If this returns a non-WireId(), then unbinding that wire
will make the given pip available.
*BaseArch default: returns empty `WireId()`*
### NetInfo \*getConflictingPipNet(PipId pip) const
If this returns a non-nullptr, then unbinding that entire net
will make the given pip available.
*BaseArch default: returns empty `getBoundPipNet(pip)`*
### AllPipsRangeT getPips() const
Return a list of all pips on the device.
### WireId getPipSrcWire(PipId pip) const
Get the source wire for a pip.
### WireId getPipDstWire(PipId pip) const
Get the destination wire for a pip.
Bi-directional switches (transfer gates) are modeled using two
anti-parallel pips.
### DelayInfo getPipDelay(PipId pip) const
Get the delay for a pip.
### DownhillPipRangeT getPipsDownhill(WireId wire) const
Get all pips downhill of a wire, i.e. pips that use this wire as source wire.
### DownhillPipRangeT getPipsUphill(WireId wire) const
Get all pips uphill of a wire, i.e. pips that use this wire as destination wire.
Group Methods
-------------
### GroupId getGroupByName(IdStringList name) const
Lookup a group by its name, which is a list of IdStrings joined by `getNameDelimiter()`.
*BaseArch default: returns `GroupId()`*
### IdStringList getGroupName(GroupId group) const
Get the name for a group. (Group names must be unique.)
*BaseArch default: returns `IdStringList()`*
### AllGroupsRangeT getGroups() const
Get a list of all groups on the device.
*BaseArch default: returns default-constructed range*
### GroupBelsRangeT getGroupBels(GroupId group) const
Get a list of all bels within a group.
*BaseArch default: asserts false as unreachable due to there being no groups*
### GroupWiresRangeT getGroupWires(GroupId group) const
Get a list of all wires within a group.
*BaseArch default: asserts false as unreachable due to there being no groups*
### GroupPipsRangeT getGroupPips(GroupId group) const
Get a list of all pips within a group.
*BaseArch default: asserts false as unreachable due to there being no groups*
### GroupGroupsRangeT getGroupGroups(GroupId group) const
Get a list of all groups within a group.
*BaseArch default: asserts false as unreachable due to there being no groups*
Delay Methods
-------------
### delay\_t estimateDelay(WireId src, WireId dst) const
Return a rough estimate for the total `maxDelay()` delay from the given src wire to
the given dst wire.
This should return a low upper bound for the fastest route from `src` to `dst`.
Or in other words it should assume an otherwise unused chip (thus "fastest route").
But it only produces an estimate for that fastest route, not an exact
result, and for that estimate it is considered more acceptable to return a
slightly too high result and it is considered less acceptable to return a
too low result (thus "low upper bound").
### delay\_t predictDelay(const NetInfo \*net\_info, const PortRef &sink) const
Return a reasonably good estimate for the total `maxDelay()` delay for the
given arc. This should return a low upper bound for the fastest route for that arc.
### delay\_t getDelayEpsilon() const
Return a small delay value that can be used as small epsilon during routing.
The router will for example not re-calculate cached routing data if faster routes
are found when the difference is smaller than this value.
### delay\_t getRipupDelayPenalty() const
The base penality when calculating delay penalty for ripping up routed nets. The
actual penalty used is a multiple of this value (i.e. a weighted version of this value).
### float getDelayNS(delay\_t v) const
Convert an `delay_t` to an actual real-world delay in nanoseconds.
### DelayInfo getDelayFromNS(float v) const
Convert a real-world delay in nanoseconds to a DelayInfo with equal min/max rising/falling values.
### uint32\_t getDelayChecksum(delay\_t v) const
Convert a `delay_t` to an integer for checksum calculations.
### bool getBudgetOverride(const NetInfo \*net\_info, const PortRef &sink, delay\_t &budget) const
Overwrite or modify (in-place) the timing budget for a given arc. Returns a bool to indicate whether this was done.
*BaseArch default: returns false*
Flow Methods
------------
### bool pack()
Run the packer.
### bool place()
Run the placer.
### bool route()
run the router.
Graphics Methods
----------------
###DecalGfxRangeT getDecalGraphics(DecalId decal) const
Return the graphic elements that make up a decal.
The same decal must always produce the same list. If the graphics for
a design element changes, that element must return another decal.
*BaseArch default: asserts false as unreachable due to there being no decals*
### DecalXY getBelDecal(BelId bel) const
Return the decal and X/Y position for the graphics representing a bel.
*BaseArch default: returns `DecalXY()`*
### DecalXY getWireDecal(WireId wire) const
Return the decal and X/Y position for the graphics representing a wire.
*BaseArch default: returns `DecalXY()`*
### DecalXY getPipDecal(PipId pip) const
Return the decal and X/Y position for the graphics representing a pip.
*BaseArch default: returns `DecalXY()`*
### DecalXY getGroupDecal(GroupId group) const
Return the decal and X/Y position for the graphics representing a group.
*BaseArch default: returns `DecalXY()`*
Cell Delay Methods
------------------
### bool getCellDelay(const CellInfo \*cell, IdString fromPort, IdString toPort, DelayInfo &delay) const
Returns the delay for the specified path through a cell in the `&delay` argument. The method returns
false if there is no timing relationship from `fromPort` to `toPort`.
*BaseArch default: returns false*
### TimingPortClass getPortTimingClass(const CellInfo \*cell, IdString port, int &clockInfoCount) const
Return the _timing port class_ of a port. This can be a register or combinational input or output; clock input or
output; general startpoint or endpoint; or a port ignored for timing purposes. For register ports, clockInfoCount is set
to the number of associated _clock edges_ that can be queried by getPortClockingInfo.
*BaseArch default: returns `TMG_IGNORE`*
### TimingClockingInfo getPortClockingInfo(const CellInfo \*cell, IdString port, int index) const
Return the _clocking info_ (including port name of clock, clock polarity and setup/hold/clock-to-out times) of a
port. Where ports have more than one clock edge associated with them (such as DDR outputs), `index` can be used to obtain
information for all edges. `index` must be in [0, clockInfoCount), behaviour is undefined otherwise.
*BaseArch default: asserts false as unreachable*
Bel Buckets Methods
-------------------
Bel buckets are subsets of BelIds and cell types used by analytic placer to
seperate types of bels during placement. The buckets should form an exact
cover over all BelIds and cell types.
Each bel bucket should be BelIds and cell types that are roughly
interchangable during placement. Typical buckets are:
- All LUT bels
- All FF bels
- All multipliers bels
- All block RAM bels
- etc.
The bel buckets will be used during analytic placement for spreading prior to
strict legality enforcement. It is not required that all bels within a bucket
are strictly equivelant.
Strict legality step will enforce those differences, along with additional
local constraints. `isValidBelForCell`, `isValidBelForCellType`, and
`isBelLocationValid` are used to enforce strict legality checks.
### BelBucketRangeT getBelBuckets() const
Return a list of all bel buckets on the device.
*BaseArch default: the list of buckets created by calling `init_bel_buckets()`, based on calls to `getBelBucketForBel` for all bels*
### IdString getBelBucketName(BelBucketId bucket) const
Return the name of this bel bucket.
*BaseArch default: `bucket`, if `BelBucketId` is a typedef of `IdString`*
### BelBucketId getBelBucketByName(IdString bucket\_name) const
Return the BelBucketId for the specified bucket name.
*BaseArch default: `bucket_name`, if `BelBucketId` is a typedef of `IdString`*
### BelBucketId getBelBucketForBel(BelId bel) const
Returns the bucket for a particular bel.
*BaseArch default: `getBelBucketForCellType(getCellType(bel))`*
### BelBucketId getBelBucketForCell(IdString cell\_type) const
Returns the bel bucket for a particular cell type.
*BaseArch default: `getBelBucketByName(cell_type)`*
### BucketBelRangeT getBelsInBucket(BelBucketId bucket) const
Return the list of bels within a bucket.
*BaseArch default: the list of bels in the bucket created by calling `init_bel_buckets()`*
Placer Methods
--------------
### bool isValidBelForCellType(IdString cell\_type, BelId bel) const
Returns true if the given cell can be bound to the given bel. This check
should be fast, compared with isValidBelForCell. This check should always
return the same value regardless if other cells are placed within the fabric.
*BaseArch default: returns `cell_type == getBelType(bel)`*
### bool isValidBelForCell(CellInfo \*cell, BelId bel) const
Returns true if the given cell can be bound to the given bel, considering
other bound resources. For example, this can be used if there is only
a certain number of different clock signals allowed for a group of bels.
*BaseArch default: returns true*
### bool isBelLocationValid(BelId bel) const
Returns true if a bell in the current configuration is valid, i.e. if
`isValidBelForCell()` would return true for the current mapping.
*BaseArch default: returns true*
### static const std::string defaultPlacer
Name of the default placement algorithm for the architecture, if
`--placer` isn't specified on the command line.
### static const std::vector\<std::string\> availablePlacers
Name of available placer algorithms for the architecture, used
to provide help for and validate `--placer`.
### static const std::string defaultRouter
Name of the default router algorithm for the architecture, if
`--router` isn't specified on the command line.
### static const std::vector\<std::string\> availableRouters
Name of available router algorithms for the architecture, used
to provide help for and validate `--router`.
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