In reply to baladevi:
Hi,
//if you want to print the value in the ns:
$timeformat(-9, 3, "ns", 8);
//$timeformat params:
//1) Scaling factor (–9 for nanoseconds, –12 for picoseconds)
//2) Number of digits to the right of the decimal point
//3) A string to print after the time value
//4) Minimum field width
//if you want to print the value in the ps:
$timeformat(-12, 3, "ps", 8);