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70V28L20PFGI Datasheet, PDF (9/17 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 Semaphore Read after Write Timing, Either Side(1)
tSAA
A0-A2
SEM
I/O
R/W
VALID ADDRESS
tAW
tWR
tEW
tDW
DATAIN VALID
tAS
tWP
tDH
VALID ADDRESS
tACE
tSOP
tOH
DATAOUT
VALID(2)
tSWRD
tAOE
OE
tSOP
Write Cycle
Read Cycle
NOTES:
1. CE = VIH or UB and LB = VIH for the duration of the above timing (both write and read cycle) (Refer to Chip Enable Truth Table).
2. "DATAOUT VALID" represents all I/O's (I/O0 - I/O15) equal to the semaphore value.
4849 drw 09 .
Timing Waveform of Semaphore Write Contention(1,3,4)
A0"A"-A2"A"
MATCH
SIDE(2) "A"
R/W"A"
SEM"A"
A0"B"-A2"B"
SIDE(2) "B"
R/W"B"
tSPS
MATCH
SEM"B"
4849 drw 10 .
NOTES:
1. DOR = DOL = VIL, CEL = CER = VIH or both UB and LB = VIH (Refer to Chip Enable Truth Table).
2. All timing is the same for left and right ports. Port "A" may be either left or right port. "B" is the opposite from port "A".
3. This parameter is measured from R/W"A" or SEM"A" going HIGH to R/W"B" or SEM"B" going HIGH.
4. If tSPS is not satisfied,the semaphore will fall positively to one side or the other, but there is no guarantee which side will be granted the semaphore flag.
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