1 - Al Kossow's Bitsavers

CLKrWRITE -------I.~ ..~---REFRESH---....... I.~ACCESS GRANT-..II (READ) -I¢AsALERAsCASREFREQROYJ>DTACK't:S"5!. FIGURE 4B - TMS4500A/MC68000L8-MC68000L 10 TIMING DIAGRAM(:;'Q)r+0':::JThe following calculations reflect gated R/W operation.t/)5' 1. Refresh time....~ Refresh interval = 1.56 msi TWST = 0, FS1 = 1, FSOr+0':::J2, Memory precharge timea. Access cyclestRP = 2(T) + to - tClSH - tp832 - tAEH-REH - ttREH + tp74 + tAEl-REl *Where to = Oelay between ClK and (j>tp832 = Propagation delay (MAX 74S832 Spec_)tP74 = Propagation delay (MIN 74S74 Spec.)andto = 1/2(tC) + tp04 -tc = 20 MHz clock cycle timetp04 = Propagation delay (MIN 74S04 Spec.)ts = Skew between ClK and (j>ts9-78