Improve archapi doc
Signed-off-by: Clifford Wolf <clifford@clifford.at>
This commit is contained in:
Clifford Wolf
parent
29dd98420b
commit
0038fe268e
339
docs/archapi.md
339
docs/archapi.md
@ -9,7 +9,7 @@ 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
|
||||
### delay\_t
|
||||
|
||||
A scalar type that is used to represent delays. May be an integer or float type.
|
||||
|
||||
@ -127,7 +127,7 @@ Get the X/Y/Z location of a given bel.
|
||||
|
||||
Lookup a bel by its X/Y/Z location.
|
||||
|
||||
### const_range\<BelId\> getBelsByTile(int x, int y) const
|
||||
### const\_range\<BelId\> getBelsByTile(int x, int y) const
|
||||
|
||||
Return a list of all bels at the give X/Y location.
|
||||
|
||||
@ -135,18 +135,22 @@ Return a list of all bels at the give X/Y location.
|
||||
|
||||
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.
|
||||
|
||||
### uint32_t getBelChecksum(BelId bel) const
|
||||
### uint32\_t getBelChecksum(BelId bel) const
|
||||
|
||||
Return a checksum for the state of a bel. (Used to calculate the design checksum.)
|
||||
Return a (preferably unique) number that represents this bel. This is used in design state checksum calculations.
|
||||
|
||||
### void bindBel(BelId bel, IdString cell, PlaceStrength strength)
|
||||
|
||||
Bind a given bel to a given cell with the given strength.
|
||||
|
||||
This method must also update `CellInfo::bel` and `CellInfo::belStrength`.
|
||||
|
||||
### void unbindBel(BelId bel)
|
||||
|
||||
Unbind a bel.
|
||||
|
||||
This method must also update `CellInfo::bel` and `CellInfo::belStrength`.
|
||||
|
||||
### 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.
|
||||
@ -159,7 +163,7 @@ Return the cell the given bel is bound to, or `IdString()` if the bel is not bou
|
||||
|
||||
If the bel is unavailable, and unbinding a single cell would make it available, then this method must return the name of that cell.
|
||||
|
||||
### const_range\<BelId\> getBels() const
|
||||
### const\_range\<BelId\> getBels() const
|
||||
|
||||
Return a list of all bels on the device.
|
||||
|
||||
@ -175,108 +179,291 @@ Return the wire connected to the given bel pin.
|
||||
|
||||
Return the type (input/output/inout) of the given bel pin.
|
||||
|
||||
### const_range\<PortPin\> getBelPins(BelId bel) const
|
||||
### const\_range\<PortPin\> getBelPins(BelId bel) const
|
||||
|
||||
Return a list of all pins on that bel.
|
||||
|
||||
Wire Methods
|
||||
------------
|
||||
|
||||
```
|
||||
WireId getWireByName(IdString name) const
|
||||
IdString getWireName(WireId wire) const
|
||||
IdString getWireType(WireId wire) const
|
||||
uint32_t getWireChecksum(WireId wire) const
|
||||
void bindWire(WireId wire, IdString net, PlaceStrength strength)
|
||||
void unbindWire(WireId wire)
|
||||
bool checkWireAvail(WireId wire) const
|
||||
IdString getBoundWireNet(WireId wire) const
|
||||
IdString getConflictingWireNet(WireId wire) const
|
||||
DelayInfo getWireDelay(WireId wire) const
|
||||
const_range<WireId> getWires() const
|
||||
const_range<BelPin> getWireBelPins(WireId wire) const
|
||||
```
|
||||
### WireId getWireByName(IdString name) const
|
||||
|
||||
Lookup a wire by its name.
|
||||
|
||||
### IdString 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()`.
|
||||
|
||||
### uint32\_t getWireChecksum(WireId wire) const
|
||||
|
||||
Return a (preferably unique) number that represents this wire. This is used in design state checksum calculations.
|
||||
|
||||
### void bindWire(WireId wire, IdString 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 `NetInfo::wires`.
|
||||
|
||||
### 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`.
|
||||
|
||||
### bool checkWireAvail(WireId wire) const
|
||||
|
||||
Return true if the wire is available, i.e. can be bound to a net.
|
||||
|
||||
### IdString getBoundWireNet(WireId wire) const
|
||||
|
||||
Return the net a wire is bound to.
|
||||
|
||||
### IdString getConflictingWireNet(WireId wire) const
|
||||
|
||||
If this returns a non-empty IdString, then unbinding that net
|
||||
will make the given wire available.
|
||||
|
||||
This returns an empty IdString if the wire is already available,
|
||||
or if there is no single net that can be unbound to make this
|
||||
wire available.
|
||||
|
||||
### DelayInfo getWireDelay(WireId wire) const
|
||||
|
||||
Get the delay for a wire.
|
||||
|
||||
### const\_range\<WireId\> getWires() const
|
||||
|
||||
Get a list of all wires on the device.
|
||||
|
||||
### const\_range\<BelPin\> getWireBelPins(WireId wire) const
|
||||
|
||||
Get a list of all bel pins attached to a given wire.
|
||||
|
||||
Pip Methods
|
||||
-----------
|
||||
|
||||
```
|
||||
PipId getPipByName(IdString name) const
|
||||
IdString getPipName(PipId pip) const
|
||||
IdString getPipType(PipId pip) const
|
||||
uint32_t getPipChecksum(PipId pip) const
|
||||
void bindPip(PipId pip, IdString net, PlaceStrength strength)
|
||||
void unbindPip(PipId pip)
|
||||
bool checkPipAvail(PipId pip) const
|
||||
IdString getBoundPipNet(PipId pip) const
|
||||
IdString getConflictingPipNet(PipId pip) const
|
||||
const_range<PipId> getPips() const
|
||||
WireId getPipSrcWire(PipId pip) const
|
||||
WireId getPipDstWire(PipId pip) const
|
||||
DelayInfo getPipDelay(PipId pip) const
|
||||
const_range<PipId> getPipsDownhill(WireId wire) const
|
||||
const_range<PipId> getPipsUphill(WireId wire) const
|
||||
const_range<PipId> getWireAliases(WireId wire) const
|
||||
```
|
||||
### PipId getPipByName(IdString name) const
|
||||
|
||||
Lookup a pip by its name.
|
||||
|
||||
### IdString 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()`.
|
||||
|
||||
### uint32\_t getPipChecksum(PipId pip) const
|
||||
|
||||
Return a (preferably unique) number that represents this pip. This is used in design state checksum calculations.
|
||||
|
||||
### void bindPip(PipId pip, IdString net, PlaceStrength strength)
|
||||
|
||||
Bid a pip to a net. This also bind the destination wire of that pip.
|
||||
|
||||
This method must also update `NetInfo::wires`.
|
||||
|
||||
### void unbindPip(PipId pip)
|
||||
|
||||
Unbind a pip and the wire driven by that pip.
|
||||
|
||||
This method must also update `NetInfo::wires`.
|
||||
|
||||
### bool checkPipAvail(PipId pip) const
|
||||
|
||||
Returns true if the given pip is available to be bound to a net.
|
||||
|
||||
### IdString getBoundPipNet(PipId pip) const
|
||||
|
||||
Return the net this pip is bound to.
|
||||
|
||||
### IdString getConflictingPipNet(PipId pip) const
|
||||
|
||||
Return the net that needs to be unbound in order to make this
|
||||
pip available.
|
||||
|
||||
This does not need to (but may) return the conflicting wire if the conflict is
|
||||
limited to the conflicting wire being bound to the destination wire for this
|
||||
pip.
|
||||
|
||||
### const\_range\<PipId\> 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 modelled using two
|
||||
antiparallel pips.
|
||||
|
||||
### DelayInfo getPipDelay(PipId pip) const
|
||||
|
||||
Get the delay for a pip.
|
||||
|
||||
### const\_range\<PipId\> getPipsDownhill(WireId wire) const
|
||||
|
||||
Get all pips downhill of a wire, i.e. pips that use this wire as source wire.
|
||||
|
||||
### const\_range\<PipId\> getPipsUphill(WireId wire) const
|
||||
|
||||
Get all pips uphill of a wire, i.e. pips that use this wire as destination wire.
|
||||
|
||||
### const\_range\<PipId\> getWireAliases(WireId wire) const
|
||||
|
||||
Get all alias pips downhill of a wire.
|
||||
|
||||
There is no api for getting the alias pips uphill of a wire.
|
||||
|
||||
Alias pips come in antiparallel pairs if a signal can be injected on either
|
||||
side of the alias pip.
|
||||
|
||||
Group Methods
|
||||
-------------
|
||||
|
||||
```
|
||||
GroupId getGroupByName(IdString name) const
|
||||
IdString getGroupName(GroupId group) const
|
||||
const_range<GroupId> getGroups() const
|
||||
const_range<BelId> getGroupBels(GroupId group) const
|
||||
const_range<WireId> getGroupWires(GroupId group) const
|
||||
const_range<PipId> getGroupPips(GroupId group) const
|
||||
const_range<GroupId> getGroupGroups(GroupId group) const
|
||||
```
|
||||
### GroupId getGroupByName(IdString name) const
|
||||
|
||||
Lookup a group by its name.
|
||||
|
||||
### IdString getGroupName(GroupId group) const
|
||||
|
||||
Get the name for a group. (Group names must be unique.)
|
||||
|
||||
### const\_range\<GroupId\> getGroups() const
|
||||
|
||||
Get a list of all groups on the device.
|
||||
|
||||
### const\_range\<BelId\> getGroupBels(GroupId group) const
|
||||
|
||||
Get a list of all bels within a group.
|
||||
|
||||
### const\_range\<WireId\> getGroupWires(GroupId group) const
|
||||
|
||||
Get a list of all wires within a group.
|
||||
|
||||
### const\_range\<PipId\> getGroupPips(GroupId group) const
|
||||
|
||||
Get a list of all pips within a group.
|
||||
|
||||
### const\_range\<GroupId\> getGroupGroups(GroupId group) const
|
||||
|
||||
Get a list of all groups within a group.
|
||||
|
||||
Delay Methods
|
||||
-------------
|
||||
|
||||
```
|
||||
delay_t estimateDelay(WireId src, WireId dst) const
|
||||
delay_t getDelayEpsilon() const
|
||||
delay_t getRipupDelayPenalty() const
|
||||
float getDelayNS(delay_t v) const
|
||||
uint32_t getDelayChecksum(delay_t v) const
|
||||
```
|
||||
### delay\_t estimateDelay(WireId src, WireId dst) const
|
||||
|
||||
Return an 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 accaptable to return a
|
||||
slightly too high result and it is considered less accaptable to return a
|
||||
too low result (thus "low upper bound").
|
||||
|
||||
### 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.
|
||||
|
||||
### uint32\_t getDelayChecksum(delay\_t v) const
|
||||
|
||||
Convert a `delay_t` to an integer for checksum calculations.
|
||||
|
||||
Flow Methods
|
||||
------------
|
||||
|
||||
```
|
||||
bool pack()
|
||||
bool place()
|
||||
bool route()
|
||||
```
|
||||
### bool pack()
|
||||
|
||||
Run the packer.
|
||||
|
||||
### bool place()
|
||||
|
||||
Run the placer.
|
||||
|
||||
### bool route()
|
||||
|
||||
run the router.
|
||||
|
||||
Graphics Methods
|
||||
----------------
|
||||
|
||||
```
|
||||
const_range<GraphicElement> getDecalGraphics(DecalId decal) const
|
||||
DecalXY getFrameDecal() const
|
||||
DecalXY getBelDecal(BelId bel) const
|
||||
DecalXY getWireDecal(WireId wire) const
|
||||
DecalXY getPipDecal(PipId pip) const
|
||||
DecalXY getGroupDecal(GroupId group) const
|
||||
```
|
||||
### const\_range\<GraphicElement\> 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.
|
||||
|
||||
### DecalXY getBelDecal(BelId bel) const
|
||||
|
||||
Return the decal and X/Y position for the graphics representing a bel.
|
||||
|
||||
### DecalXY getWireDecal(WireId wire) const
|
||||
|
||||
Return the decal and X/Y position for the graphics representing a wire.
|
||||
|
||||
### DecalXY getPipDecal(PipId pip) const
|
||||
|
||||
Return the decal and X/Y position for the graphics representing a pip.
|
||||
|
||||
### DecalXY getGroupDecal(GroupId group) const
|
||||
|
||||
Return the decal and X/Y position for the graphics representing a group.
|
||||
|
||||
Cell Delay Methods
|
||||
------------------
|
||||
|
||||
```
|
||||
bool getCellDelay(const CellInfo *cell, IdString fromPort, IdString toPort, DelayInfo &delay) const
|
||||
IdString getPortClock(const CellInfo *cell, IdString port) const
|
||||
bool isClockPort(const CellInfo *cell, IdString port) const
|
||||
```
|
||||
### 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`.
|
||||
|
||||
### IdString getPortClock(const CellInfo \*cell, IdString port) const
|
||||
|
||||
Returns the clock input port for the specified output port.
|
||||
|
||||
### bool isClockPort(const CellInfo \*cell, IdString port) const
|
||||
|
||||
Returns true if the specified port is a clock input.
|
||||
|
||||
Placer Methods
|
||||
--------------
|
||||
|
||||
```
|
||||
bool isValidBelForCell(CellInfo *cell, BelId bel) const
|
||||
bool isBelLocationValid(BelId bel) const
|
||||
```
|
||||
### 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.
|
||||
|
||||
### 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.
|
||||
|
||||
@ -22,6 +22,7 @@ For nextpnr we are using the following terminology.
|
||||
- **Pip**: Programmable Interconnect Point, a configurable connection in one direction between two wires
|
||||
- **Wire**: a fixed physical connection inside the FPGA between Pips and/or Bel pins.
|
||||
- **Alias**: a special automatic-on Pip to represent a permanent connection between two wires
|
||||
- **Group**: a collection of bels, pips, wires, and/or other groups
|
||||
|
||||
### Flow Terminology
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user