Task 1. Use help
1) What is the default switch for the redirect command? -file
help -v redirect # or redirect -help
2) Use the very last example in the man page, can you use the -append switch when redirecting to a variable? Yes.
man redirect
Task 2. Count library cells
Count the number of muxes and xor gates available in the technology library core_slow.db. Given that:
- Library cells can be reported using the following command: report_lib core_slow.db
- All mux cells begin with the letters mx (eg mx2a1)
- All xor gates begin with the letters xor (eg xor3b15)
1) First method
1 # Redirect library report to a variable and use regexp 2 redirect -variable rptstring {report_lib core_slow.db} 3 4 regexp -all mx $rptstring 5 -> 36 6 regexp -all cor $rptstring 7 -> 24
2) Second method
1 # Redirect the library report to a file and use the unix command grep 2 # This is the less desirable method due to the potentially large memory 3 # footprint required for the exec command 4 redirect tmp1212 {report_lib core_slow.db} 5 exec grep -c mx tmp1212 6 -> 36 7 exec grep -c xor tmp1212 8 -> 24 9 10 # Use grep without options to print each line containing a pattern 11 exec grep xor tmp1212 12 # Delete the file if desired 13 file delete tmp1212
Task 3. Analyze an unfamiliar script
1 proc clock_domain {args} { 2 3 # This Tcl procedure identifies the clocks constraining input ports 4 foreach_in_collection each_port [get_ports -quiet $args] { 5 6 set paths [get_timing_paths -from $each_port] 7 foreach_in_collection each_path $paths { 8 lappend port_array([get_object_name $each_port]) 9 [get_object_name [get_attribute $each_path endpoint_clock]] 10 } 11 } 12 13 foreach item [array names port_array] { 14 echo "$item $port_array($item)" 15 } 16 }
1) How many commands are in this script? 12 commands
Use the aquare brackets to help identify the embeddd commands.
2) How many occurrences of variable substitution are there? 8 occurrences
Use the $ to help identify the variable names. This procedure is using a type of variable called arrays.
3) How many arguments are required for the proc command (recall that {} are used to identify a single argument)?
3 argumets. proc clock_domain {args} {body}
4) What symbol designates a comment in a script? #
5) What symbol will continute a command over several lines?