
IDT7019L
High-Speed 128K x 9 Dual-Port Static RAM
Industrial and Commercial Temperature Ranges
Timing Waveform of Write Cycle No. 1, R/ W Controlled Timing (1,5,8)
t WC
ADDRESS
CE or SEM
OE
(9,10)
t AW
t HZ
(7)
t AS (6)
t WP (2)
t WR
(3)
R/ W
t WZ
(7)
t OW
DATA OUT
(4)
t DW
t DH
(4)
DATA IN
4840 drw 07
Timing Waveform of Write Cycle No. 2, CE Controlled Timing (1,5)
t WC
ADDRESS
t AW
CE or SEM (9,10)
t WR
t AS
(6)
t EW (2)
(3)
R/ W
t DW
t DH
DATA IN
4840 drw 08
NOTES:
1. R/ W or CE = V IH during all address transitions.
2. A write occurs during the overlap (t EW or t WP ) of a CE = V IL and a R/ W = V IL for memory array writing cycle.
3. t WR 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 = V IL transition occurs simultaneously with or after the R/ W = V IL 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 = V IL during R/ W controlled write cycle, the write pulse width must be the larger of t WP or (t WZ + t DW ) to allow the I/O drivers to turn off and data to be
placed on the bus for the required t DW . If OE = V IH during an R/ W controlled write cycle, this requirement does not apply and the write pulse can be as short as the
specified t WP .
9. To access RAM, CE = V IL and SEM = V IH . To access semaphore, CE = V IH and SEM = V IL . t EW must be met for either condition.
10. Refer to Chip Enable Truth Table.
8