25
COMMERCIALTEMPERATURERANGE
IDT723653/723663/723673 CMOS SyncFIFOTM WITH BUS-MATCHING
2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2
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 = 2,048 for the IDT723653, 4,096 for the IDT723663, 8,192 for the IDT723673.
4. If Port B size is word or byte, tSKEW2 is referenced from the rising CLKB edge that reads the last word or byte of the long word, respectively.
Figure 16. Timing for
AF
AF when the FIFO is Almost-Full (IDT Standard and FWFT Modes).
AF
CLKA
ENB
5610 drw18
ENA
CLKB
12
tSKEW2
tENS2
tENH
tPAF
tENS2
tENH
tPAF
[D-(Y+1)] Words in FIFO
(D-Y) Words in FIFO
(1)
5610 drw19
CLKA
ENA
A0-A35
MBA
CSA
W/RA
CLKB
MBF1
CSB
MBB
ENB
B0-B35
W/RB
tENS1
tENH
tDS
tDH
tPMF
tENS2
tENH
tDIS
tEN
tMDV
tPMR
FIFO Output Register
W1 (Remains valid in Mail1 Register after read)
tENS1
tENH
tENS2
tENH
tENS2
W1