It's a CPLD, so you can't replace it with another part unless you
can program the same bits into it.
AFAIK, there isn't any second-source for the CY3C37x series.
I just found a AMD MACH110, which is suppose to be a replacement.
I found that Cypress has a 7c371i version. Don't know the difference
between the ' non-i ' and the ' i ' part yet. Still looking for a
datasheet.