33
COMMERCIALTEMPERATURERANGE
IDT723656/723666/723676 CMOS TRIPLE BUS SyncFIFOTM WITH
BUS MATCHING 2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2
NOTES:
1. tSKEW2 is the minimum time between a rising CLKC edge and a rising CLKA edge for
AFC to transition HIGH in the next CLKC cycle. If the time between the rising CLKC edge and rising
CLKA edge is less than tSKEW2, then
AFC may transition HIGH one CLKC cycle later than shown.
2. FIFO2 write (MBC = 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 = 2,048 for the IDT723656, 4,096 for the IDT723666, 8,192 for the IDT723676.
4. Port C size is word or byte,
AFC is set LOW by the last word or byte write of the long word, respectively.
Figure 27. Timing for
AFC
AFC when FIFO2 is Almost-Full (IDT Standard and FWFT Modes)
Figure 25. Timing for
AEA
AEA when FIFO2 is Almost-Empty (IDT Standard and FWFT Modes)
Figure 26. Timing for
AFA
AFA when FIFO1 is Almost-Full (IDT Standard and FWFT Modes)
NOTES:
1. tSKEW2 is the minimum time between a rising CLKC edge and a rising CLKA edge for
AEA to transition HIGH in the next CLKA cycle. If the time between the rising CLKC edge and rising
CLKA edge is less than tSKEW2, then
AEA may transition HIGH one CLKA cycle later than shown.
2. FIFO2 Write (MBC = LOW), FIFO2 read (
CSA = LOW, W/RA = LOW, MBA = LOW). Data in the FIFO2 output register has been read from the FIFO.
3. If Port C size is word or byte, tSKEW2 is referenced to the rising CLKC edge that writes the last word or byte of the long word, respectively.
NOTES:
1. tSKEW2 is the minimum time between a rising CLKA edge and a rising CLKB edge for
AFA 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
AFA may transition HIGH one CLKA cycle later than shown.
2. FIFO1 Write (
CSA = LOW, W/RA = HIGH, MBA = LOW), FIFO1 read (CSB = LOW, MBB = LOW). Data in the FIFO1 output register has been read from the FIFO.
3. D = Maximum FIFO Depth = 2,048 for the IDT723656, 4,096 for the IDT723666, 8,192 for the IDT723676.
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.
AEA
CLKC
ENA
5611 drw 26
WENC
CLKA
2
1
tENS2
tENH
tSKEW2
tPAE
tENS2
tENH
(X2+1) Words in FIFO2
X2 Words in FIFO2
(1)
AFA
CLKA
RENB
5611 drw 27
ENA
CLKB
12
tSKEW2
tENS2
tENH
tPAF
tENS2
tENH
tPAF
[D-(Y1+1)] Words in FIFO1
(D-Y1) Words in FIFO1
(1)
AFC
CLKC
ENA
5611 drw 28
WENC
CLKA
12
tSKEW2
tENS2
tENH
tPAF
tENS2
tENH
tPAF
[D-(Y2+1)] Words in FIFO2
(D-Y2) Words in FIFO2
(1)