<DATAPATHMODIFYFUNCTION

"DATAPATH MODIFY FUNCTION

Modifies the placement constraints for a function in a Datapath Region.

Syntax

     DA*TAPATH M*ODIFY F*UNCTION
       NA*ME functionInstanceName
       [B*ITOFFSET bitOffsetValue]
       [E*XTRATRACK extraTrackValue]
       [S*TACKABLE | NOS*TACKABLE]
       [F*LIP | NOF*LIP];


Arguments

NAME regionName string
Required argument that specifies the name of the region to be edited. The 'regionName' must be the name as specified in the NAME option of the DATAPATH ADD REGION command that created the region.

BITOFFSET bitOffsetValue int 
Optional argument to specify the bit offset of the named function from zero. The default offset is -1, which is a flag to let the placer know that it can set the bitOffSet to minimize wire/net length during placement. The net result is that the function may move vertically to allow better alignment of itself to other functions in the region. If the user sets this value, then the user is telling the placer that this function must be kept at a pre-determined offset from zero to keep the user defined alignment between the functions.

EXTRATRACK extraTrackValue int 
Optional argument specifying the number of tracks to the right of the function to reserve during datapath placement. This is a user definable constraint to allow control over vertical routing congestion or to just reserve space next to a particular function (say for specific random logic that was not included in the generator or tile file description of the function).

STACKABLE boolean
Optional argument specifying that the named function is allowed to be stacked vertically above or below other functions in the region during datapath placement. Cannot be used with the NOSTACKABLE option as they are mutually exclusive.

NOSTACKABLE boolean
Optional argument specifying that the named function is NOT allowed to be vertically stacked above or below other functions in the region during datapath placement. Cannot be used with the STACKABLE option as they are mutually exclusive.

FLIP boolean
Optional argument specifying that the named function is allowed to be flipped horizontally during datapath placement. Cannot be used with the NOFLIP option as they are mutually exclusive.

NOFLIP boolean
Optional argument specifying that the named function is NOT allowed to be flipped horizontally during datapath placement. Cannot be used with the FLIP option as they are mutually exclusive.


Description

This command is an optional step that allows the user to set the placement constraints of a function in a previously created Datapath region in the design. It allows the user to change -

The bit offset of the function from zero - BITOFFSET
The extra tracks to the right of the function - EXTRATRACK
The stackability of the function - STACKABLE | NOSTACKABLE
The ability to flip the function horizontally - FLIP | NOFLIP

This command can be used by the user to manually override a functions constraints.


Environmental Variables

None


Examples

DATAPATH MODIFY FUNCTION NAME I123 BITOFFSET 4 STACKABLE;

Updates the constraints of the function 'I123' such that the placer has to offset the vertical position of this function such that bit zero aligns with bit 4 of it's neighboring function, and allows the placer to stack this function above another function if possible.

DATAPATH MODIFY FUNCTION NAME I123 NOSTACKABLE NOFLIP;

Updates the constraints of the function 'I123' such that the placer cannot stack this function above any other and no flipping of the function is allowed.


Related Commands

DATAPATH PLACE
DATAPATH MODIFY REGION"

	<Type QHELP>
	<Header "Datapath Modify Region Command Help">
>
