assign_local_clock (Axcelerator)

Assigns regular nets to local clock routing.

assign_local_clock -type value -net netname [LocalClock_region]+

Note: Along with the netlist, import PDC files as source files because the compiler needs to insert or delete buffers as well as legalize the netlist.

Arguments

-type value

Specifies the type of clock to which the net will be assigned. You can enter one of the following values:

Note: Nets currently assigned to hclk or rclk are not demoted. Therefore, nets currently assigned to routed clocks or hardwired clocks cannot be assigned to local clocks. Also, hardwired clock (hclk) networks can only drive clock pins.

-net netname

Specifies the name of the net to assign to a LocalClock region. You must specify a net name that currently exists in the design.

LocalClock_region

You must specify at least one LocalClock region. You can define the LocalClock region at either the tile level or at the row or column level within a tile.

You can define the LocalClock region at the tile level as follows: tile<number><letter>. The tiles are numbered 1,2,3, .. in the Y axis and A, B, C, … in the X axis. Tile1A is the lower-left tile. In addition, you can cascade LocalClock regions by specifying into which tiles to assign the user-specified net. Refer to the examples below.

You can also define the LocalClock region at the row or column level within a tile as follows: tile<number><letter>.row<number> | col<number>. Whether you select a row or a column depends on whether you are specify hclk or rclk for the LocalClock region. Refer to the examples below. When defining a row, ensure that the LocalClock region is composed of at least two consecutive rows.

LocalClock assignment uses resources remaining after global assignment from Input Netlist. Axcelerator devices can include a total of four routed clock and four hardwired clock networks.

Supported Families

Axcelerator

Exceptions

• The assign_local_clock command is not supported in auxiliary PDC files. If importing a PDC file that includes this command, you must import it as a source file.

Examples

You can cascade tiles to create one LocalClock region as follows:

assign_local_clock -type hclk -net  reset_n tile1a tile2a

assign_local_clock -type rclk -net  reset_n tile1a tile2a

You can assign a net to one tile as follows:

assign_local_clock -type rclk -net  reset_n tile1a

assign_local_clock -type hclk -net  reset_n tile2c

You can assign a net to a column within a tile as follows:

assign_local_clock -type hclk -net  reset_n tile1a.col7  tile2a.col9

You can assign a net to a row within a tile as follows:

assign_local_clock -type rclk -net  reset_n tile1a.row4 tile1a.row5

See Also

Assign net to local clock

assign_global_clock

assign_local_clock (Fusion and ProASIC3/E)

unassign_local_clock

PDC syntax conventions

PDC naming conventions