Comparison of 1G123 to 4538
A CPLD would be the wrong tool for the job. At this time scale, a microcontroller is much more appropriate. Even a tiny PIC10F200 running on its &plusmn;2% internal oscillator would have enough precision for your application. You can get one in an SOT23-6 package for less than 50 cents, and the only external component required is a bypass capacitor.