How to split a delimited string into an array in awk?

How to split the string when it contains pipe symbols | in it.
I want to split them to be in array.

I tried

echo "12:23:11" | awk '{split($0,a,":"); print a[3] a[2] a[1]}'

Which works fine. If my string is like "12|23|11" then how do I split them into an array?