25
COMMERCIAL TEMPERATURERANGE
IDT72V3623/72V3633/72V3643 CMOS 3.3V SyncBiFIFOTM WITH BUS-MATCHING
256 x 36, 512 x 36, 1,024 x 36
Figure 17. Timing for Mail1 Register and
MBF1
MBF1 Flag (IDT Standard and FWFT Modes)
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).
NOTES:
1. tSKEW2 is the minimum time between a rising CLKA edge and a rising CLKB edge for
AF to transition HIGH in the next CLKA cycle. If the time between the rising CLKA edge and
rising CLKB edge is less than tSKEW2, then
AF may transition HIGH one CLKA cycle later than shown.
2. FIFO Write (
CSA = LOW, W/RA = HIGH, MBA = LOW), FIFO read (CSB = LOW, W/RB = HIGH, MBB = LOW). Data in the FIFO output register has been read from the FIFO.
3. D = Maximum FIFO Depth = 256 for the IDT72V3623, 512 for the IDT72V3633, 1,024 for the IDT72V3643.
4. If Port B size is word or byte, tSKEW2
Figure 16. Timing for
AF
AF when the FIFO is Almost-Full (IDT Standard and FWFT Modes).
AF
CLKA
ENB
4662 drw 18
ENA
CLKB
12
tSKEW2
tENH
tPAF
tENH
tPAF
[D-(Y+1)] Words in FIFO
(D-Y) Words in FIFO
(1)
tENS2
4662 drw19
CLKA
ENA
A0-A35
MBA
CSA
W/RA
CLKB
MBF1
CSB
MBB
ENB
B0-B35
W/RB
tENH
tDS
tDH
tPMF
tENH
tDIS
tEN
tMDV
tPMR
FIFO Output Register
W1 (Remains valid in Mail1 Register after read)
tENH
W1
tENS1
tENS2