memory products - Al Kossow's Bitsavers

MK4S03(N, K)-S0/6S/80110112/1S/20HALF FULL FLAG LOGICWhen in single device configuration, the (HF) outputacts as an indication of a half full memory. Afterhalf of the memory is filled, and at the falling~e of the next write operation, the half full flag(HF) will be set low and remain low until the differ-FIGURE 9. HALF FULL FLAG TIMINGence between the write pointer and read pointer isless than or e~1 to one half the total memory. Thehalf full flag (HF) is then reset by the rising edgeof the read operation. See Figure 9.iiIIHALF-FULL~ 'wtt.HALF-FULL +1-tAHFI\'-HALF-FULLr-AC CHARACTERISTICS(O"C:sT A :s+70"C) (Vee = +5 Volts ±10%)SYM PARAMETERtWHFtRHF4503·50 4503·65 4503·80MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX Mill MAX MIN MAX ~IIITS NOTESWrite Low to Half FullFlag Low 65 80 100Raad High to Half FullFlag High 65 80 1004503·10 4503·12 4503·15 4503·20120 140 175 235 ns120 140 175 235 ns9/16421