70V28L20PFGI Datasheet, PDF (8/17 Pages) Integrated Device Technology – HIGH-SPEED 3.3V 64K x 16 DUAL-PORT STATIC RAM

IDT70V28L
High-Speed 3.3V 64K x 16 Dual-Port Static RAM
Industrial and Commercial Temperature Ranges
Timing Waveform of Write Cycle No. 1, R/W Controlled Timing^(1,5,8)
tWC
ADDRESS
tHZ ⁽⁷⁾
OE
tAW
CE or SEM^(9,10)
UB or LB⁽⁹⁾
R/W
DATAOUT
DATAIN
tAS ⁽⁶⁾
(4)
tWP ⁽²⁾
tWZ ⁽⁷⁾
tDW
tWR ⁽³⁾
tOW
tDH
(4)
4849 drw 07
Timing Waveform of Write Cycle No. 2, CE Controlled Timing^(1,5)
tWC
ADDRESS
CE or SEM^(9,10)
UB or LB⁽⁹⁾
tAS⁽⁶⁾
tAW
tEW ⁽²⁾
tWR⁽³⁾
R/W
DATAIN
tDW
tDH
4849 drw 08 ^.
NOTES:
1. R/W or CE or UB and LB = VIH during all address transitions.
2. A write occurs during the overlap (tEW or tWP) of a CE = VIL and a R/W = VIL for memory array writing cycle.
3. tWR is measured from the earlier of CE or R/W (or SEM or R/W) going HIGH to the end of write cycle.
4. During this period, the I/O pins are in the output state and input signals must not be applied.
5. If the CE or SEM = VIL transition occurs simultaneously with or after the R/W = VIL transition, the outputs remain in the High-impedance state.
6. Timing depends on which enable signal is asserted last, CE or R/W.
7. This parameter is guaranteed by device characterization, but is not production tested. Transition is measured 0mV from steady state with the Output Test Load
(Figure 2).
8. If OE = VIL during R/W controlled write cycle, the write pulse width must be the larger of tWP or (tWZ + tDW) to allow the I/O drivers to turn off and data to be
placed on the bus for the required tDW. If OE = VIH during an R/W controlled write cycle, this requirement does not apply and the write pulse can be as short as the
specified tWP.
9. To access RAM, CE = VIL and SEM = VIH. To access semaphore, CE = VIH and SEM = VIL. tEW must be met for either condition.
10. Refer to Truth Table I - Chip Enable.
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