Honored Contributor
Honored ContributorI just add some informations I've came across while constraint my desing.
About "set_clock_groups -asynchronous" vs "set_clock_groups -exclusive" what Rysc told is perfectly right. In FPGA Timequest treat both in the same way. The only thing usefull is that with -asyncronous parameter you can set more than 2 clock groups together, whereas -exclusive is limited to maximum of 2. Another syntax problem I came across (because I didn't find explained on Altera documentations) is the the TCL backslash use. It's used in order to make a command continue on next line because in tcl all command are closed on the line or by a ;. There is an important exception that are the use of {}. When you use { the command is not closed untill it find } so for example the correct syntax of set_clock_groups reported above shall be set_clock_groups -asynchronous -group { clk1 clk2 } -group { clk3 clk4 } -group { clk5 } so you need only the \ outside the curling brackets. That's the same also when you use the double quotes " instead of curling brackets. The difference is that if in "" you find a $var_name that will be substituted. Example: set a pippo puts "my names is $a" -> my names is pippo puts { my names is $a } -> my names is $a
