23
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT723616 CMOS TRIPLE BUS SyncFIFO
™™
™™
™ WITH
BUS-MATCHING AND BYTE SWAPPING 64 x 36 x 2
AEB
CLKA
RENB
3520 drw16
ENA
CLKB
2
1
tENS tENH
tSKEW2
tPAE
tPAE
tENS tENH
X Long Word in FIFO1
(X+1) Long Words in FIFO1
(1)
NOTES:
1. tSKEW2 is the minimum time between a rising CLKA edge and a rising CLKB edge for AEB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA
edge and rising CLKB edge is less than tSKEW2, then AEB may transition HIGH one CLKB cycle later than shown.
2. FIFO1 Write (CSA = LOW, W/RA = HIGH).
3. Port-B size is word or byte; AEB is set LOW by the last word or byte read of the long word, respectively.
Figure 16. Timing for AEB when FIFO1 is Almost-Empty
Figure 17. Timing for
AEAAEA
AEAAEA
AEA
when FIFO2 is Almost-Empty
AEA
CLKC
ENA
3520 drw17
WENC
CLKA
2
1
t
ENS
t
ENH
t
SKEW2
t
PAE
t
PAE
t
ENS
t
ENH
(X+1) Long Words in FIFO2
X Long Words in FIFO2
(1)
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 read (CSA = LOW, W/RA = LOW).
3. Port-C size is word or byte; tSKEW2 is referenced from the rising CLKC edge that writes the last word or byte of the long word, respectively.
CSA
EFA
ENA
A0 - A35
CLKA
FFC
CLKC
3520 drw15
12
C0 - C17
WENC
t
CLK
t
CLKH
t
CLKL
t
ENS
t
ENH
t
A
t
SKEW1
t
CLK
t
CLKH
t
CLKL
t
ENS
t
DS
t
ENH
t
DH
To FIFO2
Previous Word in FIFO2 Output Register
Next Word From FIFO2
LOW
W/RA
LOW
HIGH
(1)
FIFO2 Full
t
WFF
t
WFF
t
DH
t
DS
Figure 15.
FFCFFC
FFCFFC
FFC
Flag Timing and First Available Write when FIFO2 is Full
NOTES:
1. tSKEW1 is the minimum time between a rising CLKA edge and a rising CLKB edge for FFB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge
and rising CLKB edge is less than tSKEW1, then FFB may transition HIGH one CLKB cycle later than shown.
2. Port-C size is word or byte; FFC is set LOW by the last word or byte write of the long word, respectively. (The word-size case is shown.)
