PAL IMPLEMENTED STATE MACHINE FOR MC6818
Original Publication Date: 1983-Mar-01
Included in the Prior Art Database: 2001-Oct-10
The control interface for the MC6818 real time clock can be a problem for printed circuit boards where real estate is at a premium. An alternative to a Johnson counter and gates is to build a state machine inside a PAL. The PAL is an AND-OR network with certain devices also containing D flip flops. This architecture allows several packages to be realized inside one package while retaining maximum flexibility of clock speeds.