COMMERCIAL TEMPERATURE RANGE
IDT72V3684/72V3694/72V36104 3.3V CMOS SyncBiFIFO
TM
WITH
BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65 and 536 x 36 x 2
31
Figure 26. Timing for
AFBAFB
AFBAFB
AFB
when FIFO2 is Almost-Full (IDT Standard and FWFT Modes)
Figure 27. Timing for Mail1 Register and
MBF1MBF1
MBF1MBF1
MBF1
Flag (IDT Standard and FWFT Modes)
NOTES:
1. tSKEW2 is the minimum time between a rising CLKB edge and a rising CLKA edge for AFB to transition HIGH in the next CLKB cycle. If the time between the rising CLKB edge and rising
CLKA edge is less than tSKEW2, then AFB may transition HIGH one CLKB cycle later than shown.
2. FIFO2 write (CSB = LOW, W/RB = LOW, MBB = LOW), FIFO2 read (CSA = LOW, W/RA = LOW, MBA = LOW). Data in the FIFO2 output register has been read from the FIFO.
3. D = Maximum FIFO Depth = 16,384 for the IDT72V3684, 32,768 for the IDT72V3694, 65,536 for the IDT72V36104.
4. If Port B size is word or byte, AFB is set LOW by the last word or byte write of the long word, respectively.
AFB
CLKB
ENA
4677 drw28
ENB
CLKA
12
tSKEW2
tENS2
tENH
tPAF
tENS2
tENH
tPAF
[D-(Y2+1)] Words in FIFO2
(D-Y2) Words in FIFO2
(1)
4677 drw29
CLKA
ENA
A0-A35
MBA
CSA
W/RA
CLKB
MBF1
CSB
MBB
ENB
B0-B35
W/RB
W1
tENS1
tENH
tDS
tDH
tPMF
tPMF
tENS2
tENH
tDIS
tEN
tMDV
tPMR
FIFO1 Output Register W1 (Remains valid in Mail1 Register after read)
tENS1
tENH
tENS2
tENH
tENS2
tENH
NOTE:
1. If Port B is configured for word size, data can be written to the Mail1 register using A0-A17 (A18-A35 are don't care inputs). In this first case B0-B17 will have valid data (B18-B35
will be indeterminate). If Port B is configured for byte size, data can be written to the Mail1 Register using A0-A8 (A9-A35 are don't care inputs). In this second case, B0-B8 will
have valid data (B9-B35 will be indeterminate).
