18
COMMERCIALTEMPERATURERANGE
IDT72V3624/72V3634/72V3644 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING
256 x 36 x 2, 512 x 36 x 2, 1,024 x 36 x 2
Figure 6. Serial Programming of the Almost-Full Flag and Almost-Empty Flag Offset Values (IDT Standard and FWFT Modes)
Figure 5. Parallel Programming of the Almost-Full Flag and Almost-Empty Flag Offset Values after Reset (IDT Standard and FWFT Modes)
NOTES:
1. tSKEW1 is the minimum time between the rising CLKA edge and a rising CLKB edge for
FFB/IRB to transition HIGH in the next cycle. If the time between the rising edge of CLKA and rising
edge of CLKB is less than tSKEW1, then
FFB/IRB may transition HIGH one CLKB cycle later than shown.
2. It is not necessary to program offset register bits on consecutive clock cycles. FIFO write attempts are ignored until
FFA/IRA and FFB/IRB is set HIGH.
3. Programmable offsets are written serially to the SD input in the order
AFA offset (Y1), AEB offset (X1), AFB offset (Y2), and AEA offset (X2).
NOTES:
1. tSKEW1 is the minimum time between the rising CLKA edge and a rising CLKB edge for
FFB/IRB to transition HIGH in the next cycle. If the time between the rising edge of CLKA and rising
edge of CLKB is less than tSKEW1, then
FFB/IRB may transition HIGH one CLKB cycle later than shown.
2.
CSA=LOW, W/RA=HIGH,MBA=LOW. It is not necessary to program offset register on consecutive clock cycles.
4664 drw07
CLKA
MRS1,
MRS2
FFA/IRA
CLKB
FFB/IRB
A0-A35
FS1,FS0
ENA
tFSH
tWFF
tENH
tENS2
tSKEW1
tDS
tDH
tWFF
4
0,0
AFA Offset
(Y1)
AEB Offset
(X1)
AFB Offset
(Y 2)
AEA Offset
(X 2)
First Word to FIFO1
12
(1)
tFSH
tFSS
SPM
tFSS
1
2
CLKA
FFA/IRA
tSENS
tSENH
FS0/SD(3)
tSPH
tSENS
tSENH
tFSS
tWFF
FS1/SEN
AEA Offset (X2) LSB
tSDS
tSDH
tSDS
tSDH
AFA Offset (Y1) MSB
MRS1,
MRS2
4
4664 drw08
tFSS
tFSH
CLKB
4
SPM
FFB/IRB
tWFF
tSKEW(1)