20
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT723612
CMOS SYNCBiFIFO
TM
64 x 36 x 2
COMMERCIAL AND INDUSTRIAL
FEBRUARY 13, 2009
AEA
CLKB
ENA
3136 drw15
ENB
CLKA
2
1
t
ENS2
t
ENH2
t
ENS2
t
ENH2
(X+1) Words in FIFO2
X Words in FIFO2
t
SKEW2
(1)
t
PAE
t
PAE
NOTES:
1. tSKEW2 is the minimum time between a rising CLKB edge and a rising CLKA edge for AEA to transition HIGH in the next CLKA cycle. If the time between the rising
CLKB edge and rising CLKA edge is less than tSKEW2, then AEA may transition HIGH one CLKA cycle later than shown.
2. FIFO2 Write (CSB = LOW, W/RB = HIGH, MBB = LOW), FIFO2 read (CSA = LOW, W/RA = LOW, MBA = LOW).
Figure 12. Timing for
AEAAEA
AEAAEA
AEA
when FIFO2 is Almost Empty
AFB
CLKB
ENA
3136 drw17
ENB
CLKA
12
t
ENS2
t
ENH2
t
ENS2
t
ENH2
[64-(X+1)] Words in FIFO2
(64-X) Words in FIFO2
t
PAF
t
SKEW2
(1)
t
PAF
Figure 14. Timing for
AFBAFB
AFBAFB
AFB
when FIFO2 is Almost Full
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 CLKA cycle later than shown.
2. FIFO2 Write (CSB = LOW, W/RB = HIGH, MBB = LOW), FIFO2 read (CSA = LOW, W/RA = LOW, MBA = LOW).
Figure 13. Timing for
AFAAFA
AFAAFA
AFA
when FIFO1 is Almost Full
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 CLKB cycle later than shown.
2. FIFO1 Write (CSA = LOW, W/RA = HIGH, MBA = LOW), FIFO1 read (CSB = LOW, W/RB = LOW, MBB = LOW).
AFA
CLKA
ENB
3136 drw16
ENA
CLKB
12
t
ENS2
t
ENH2
t
ENS2
t
ENH2
[64-(X+1)] Words in FIFO1
(64-X) Words in FIFO1
t
PAF
t
SKEW2
(1)
t
PAF
