You're right, that was inelegantly written and kinda conflates two different things. Gates are spread around for fixing design errors as you describe. There is

You're right, that was inelegantly written and kinda conflates two different things. Gates are spread around for fixing design errors as you describe. There is also often redundant logic and memory built in to allow fixing individual chips though. Here's a quick presentation I found on laser repairs: http://www.ee.ncu.edu.tw/~jfli/memtest/lecture/ch07.pdf http://www.ee.ncu.edu.tw/~jfli/memtest/lecture/ch07.pdf