21
COMMERCIAL TEMPERATURE RANGE
IDT72V3653/72V3663/72V3673 3.3V CMOS SyncFIFO
TM
WITH
BUS-MATCHING 2,048 x 36, 4,096 x 36, and 8,192 x 36
NOTES:
1. tSKEW1 is the minimum time between a rising CLKA edge and a rising CLKB edge for OR to transition HIGH and to clock the next word to the FIFO output register in three CLKB cycles.
If the time between the rising CLKA edge and rising CLKB edge is less than tSKEW1, then the transition of OR HIGH and load of the first word to the output register may occur one CLKB
cycle later than shown.
2. If Port B size is word or byte, OR is set LOW by the last word or byte read from the FIFO, respectively.
Figure 11. OR Flag Timing and First Data Word Fall Through when FIFO is Empty (FWFT Mode)
CSA
W/RA
MBA
IR
A0-A35
CLKB
OR
CSB
W/RB
MBB
ENA
ENB
B0-B35
CLKA
4662 drw13
12
3
tCLKH
tCLKL
tCLK
tENS2
tENS2
tENH
tENH
tDS tDH
tSKEW1
tCLK
tCLKL
tREF tREF
tENS2
tENH
tA
Old Data in FIFO Output Register W1
LOW
HIGH
LOW
HIGH
LOW
tCLKH
W1
HIGH
(1)
FIFO Empty
