com.xilinx.rapidwright.timing

Interface DelayModel

All Known Implementing Classes:

SmallDelayModel

public interface DelayModel

Provide delay lookup for logic and intra site delay. Never construct DelayModel directly. Use DelayModelBuilder to guarantee that there is at most one DelayModel. Conventions: A user see a cell with all its input and output pins. But, the user do NOT know if a timing arc between each pair of input and output exists or not. Thus, the user will call the delay model with each possible pair of input/output. If the pair does not correspond to a timing arc, -1 will be returned. the user have to interpret negative values as an indicator that the arc DOES NOT exist. The model is not context-aware. This means 1) a delay of an arc does not change with its load. 2) there is an arc even when its input or output is not connected. When the user see an input pin connected to VCC or GND, the user have to assume the responsibility of replacing the delay with 0. TODO: change interaction with user to reduce runtime. In particular, a list of timing arcs will be returned for the cell passed in by a user.

Method Summary

Modifier and Type	Method and Description
short	getBELIndex(String belName) TODO - Revisit this is part of the DelayModel Gets the equivalent timing model index for this BEL
int	getEncodedConfigCode(String value) TODO - Revisit this as part of the DelayModel Gets the encoded config code for the value (belname:paramsetting)
Short	getIntraSiteDelay(SiteTypeEnum siteTypeName, String frBelPin, String toBelPin) Get the delay in ps between two bel pins within the given site name.
short	getLogicDelay(short belIdx, String frBelPin, String toBelPin) Get the delay between input and output pins of a bel.
short	getLogicDelay(short belIdx, String frBelPin, String toBelPin, int encodedConfig) Get the delay between input and output pins of a bel.

Method Detail

getIntraSiteDelay

Short getIntraSiteDelay(SiteTypeEnum siteTypeName,
                        String frBelPin,
                        String toBelPin)

Get the delay in ps between two bel pins within the given site name.

Parameters:

siteTypeName - The name of the site type, such as SLICEL and SLICEM.

frBelPin - The bel pin which is the driver of the connection. Thus, it must be a bel output pin. The bel name must be included, ie., AFF2/D. An input site pin is considered a valid frBelPin.

toBelPin - The bel pin which is the sink of the connection (a bel input pin, or an output site pin).

Returns:

Intra-site delay in ps. Return -1 if the connection does not exist.

Throws:

IllegalArgumentException - if the given siteTypeName is not recognized by the model.

getLogicDelay

short getLogicDelay(short belIdx,
                    String frBelPin,
                    String toBelPin,
                    int encodedConfig)

Get the delay between input and output pins of a bel.

Parameters:

belIdx - The unique BEL timing model index, see DelayModel.getBELIndex(String).

frBelPin - An input bel pin. It must NOT include bel name.

toBelPin - An output bel pin. It must NOT include bel name.

encodedConfig - A list of config_name:value of the bel, ie., {CYINIT_BOT:GND, CARRY_TYPE:SINGLE_CY8}. What is the possible config_name and its value? Ones need to look at the logic delay files used for DelayModelSource_text to find that out. Where to get the config's value from the design? There is no uniform way to find the value. It is to determined per case. For example, some configs of carry8 is from bel, while some from cell.

Returns:

Logic delay in ps. Return -1 if the connection does not exist.

Throws:

IllegalArgumentException - if the given bel is not recognized by the model.

getLogicDelay

short getLogicDelay(short belIdx,
                    String frBelPin,
                    String toBelPin)

Get the delay between input and output pins of a bel.

Parameters:

belIdx - The unique BEL timing model index, see DelayModel.getBELIndex(String).

frBelPin - An input bel pin. It must NOT include bel name.

toBelPin - An output bel pin. It must NOT include bel name.

Returns:

Logic delay in ps. Return -1 if the connection does not exist.

Throws:

IllegalArgumentException - if the given bel is not recognized by the model.

getEncodedConfigCode

int getEncodedConfigCode(String value)

TODO - Revisit this as part of the DelayModel Gets the encoded config code for the value (belname:paramsetting)

Returns:

The encoded value

getBELIndex

short getBELIndex(String belName)

TODO - Revisit this is part of the DelayModel Gets the equivalent timing model index for this BEL

Parameters:

belName - Name of the BEL

Returns:

The unique BEL timing model index