Locking Cell Inputs and Adding DONT_TOUCH Constraint on LUT Loads - 2022.1 English

1. Open Device window.
2. Select the load LUT.
3. Right-click and select Lock Cell Input Pins.

The equivalent Tcl command is:

set_property LOCK_PINS {NAME:BEL_PIN} <cell object>

To prevent pin swapping in Physical Synthesis in the Placer, a DONT_TOUCH constraint needs to be applied to the LUT cell. The Tcl command is:

For nets that have fixed routing and multiple LUT loads, the following Tcl script can be used to lock the cell inputs of all the LUT loads.

set fixed_nets [get_nets -hierarchical -filter IS_ROUTE_FIXED] foreach LUT_load_pin [get_pins -leaf -of [get_nets $fixed_nets] \
-filter DIRECTION==IN&&REF_NAME=~LUT*] {
set pin [get_property REF_PIN_NAME $LUT_load_pin]
set BEL_pin [file tail [get_bel_pins -of [get_pins $LUT_load_pin]]] set LUT_name [get_property PARENT_CELL $LUT_load_pin]
# need to handle condition when LOCK_pins property already exists on LUT set existing_LOCK_PIN [get_property LOCK_PINS [get_cells $LUT_name]]
if { $existing_LOCK_PIN ne "" } {
reset_property LOCK_PINS [get_cells $LUT_name]
}
set_property LOCK_PINS \
[lsort -unique [concat $existing_LOCK_PIN $pin:$BEL_pin]] [get_cells $LUT_name]
}