Hi Boris,
problem is load_of is not an SDC command. There are a number of things you can do
(1) create a load_of procedure in TCL along the lines of
proc load_of {args} {
set libCellPath [find / -null_ok
-libpin $args]
if {$libCellPath != {}}
{
set load [get_liberty_attribute capacitance
$libCellPath]
} else {
set
load 0
}
return
$load
}
(2) User RC syntax
set_attribute external_pin_cap [expr 5 * [lindex [get_attr capacitance $load_pin] 0]] [all des outs]
note that the expression 'lindex [get_attr capacitance $load_pin] 0' is needed since it provide values for rising and falling edges. Also $load_pin is the ouput of something like 'find /libraries -libpin . ...]
hope this helps,
gh-