memory products - Al Kossow's Bitsavers

MK4S03(N, K)-SO/6S/80/1 0/12/1S/20READ MODEThe MK4503 initiates a Read Cycle (see Figure~)on the falling edge of Read Enable control input (R),provided that the Empty Flag (EF) is not asserted.In the Read mode of operation, the MK4503 providesa fast access to data from 9 of 18432 locationsin the static storage array. The data isaccessed on a FIFO basis inde~ndent of any ongoingWRITE operations. After R goes high, dataoutputs will return to a high impedance conditionuntil the next Read operation.In the event that all data has been read from theFIFO, the EF will go low, and further Read opera-tions will be inhibited ~ data outputs will remainin· high impedance). EF will go high tWEF aftercompletion of a valid Write operation. EFwill again go low tREF from the beginning a subsequentREAD operation, provided that a secondWRITE has not been completed ~e Figure 4B).Reads beginning tEFR after EL goes highare valid. Reads begun after...EF goes lowand more than tRPI before EF goes highare invalid .iliI.nored). Reads beginning less thantRPI before EF goes high and less than tEFR latermayor may not occur (be valid) depending on internalflag status.AC ELECTRICAL CHARACTERISTICS(O°C:s;TA:s; +70°C) (Vee = +5.0 volts ± 10%)SYM PARAMETER4503·50 4503·65 4503·80MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX ~NITS NOTEStRC Read Cycle Time 65 80 100tA Access Time 50 65 80tRR Read Recovery Time 15 15 20tRPW Read Pulse Width 50 65 80tRL R Low to Low Z a a atovData Valid from RHigh 5 5 5tRHZ R High to High Z 25 25 25tREF R Low to EF Low 45 60 75tEfREF High to ValidRead 10 10 10tWEF W High to EF High 45 60 75tRPIRead ProtectIndeterminant 35 35 354503·10 4503·12 4503·15 4503-20120 140 175 235 ns100 120 150 200 ns 220 20 25 35 ns100 120 150 200 ns 1a a a a ns 25 5 5 5 ns 225 35 50 60 ns 295 115 145 195 ns 210 10 10 10 ns 295 110 140 190 ns 235 35 35 35 ns 24/16416