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15
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT72V2101/72V2111 3.3V HIGH DENSITY CMOS
SUPERSYNC FIFOTM 262,144 x 9, 524,288 x 9
EF/OR is synchronous and updated on the rising edge of RCLK.
In IDT Standard mode,
EF is a double register-buffered output. In FWFT
mode,
OR is a triple register-buffered output.
PROGRAMMABLE ALMOST-FULL FLAG (
PAF)
The Programmable Almost-Full flag (
PAF) will go LOW when the FIFO
reaches the almost-full condition. In IDT Standard mode, if no reads are
performed after reset (
MRS), PAF will go LOW after (D - m) words are written
to the FIFO. The
PAF will go LOW after (262,144-m) writes for the IDT72V2101
and (524,288-m) writes for the IDT72V2111. The offset “m” is the full offset
value. The default setting for this value is stated in the footnote of Table 1.
In FWFT mode, the
PAF will go LOW after (262,145-m) writes for the
IDT72V2101 and (524,289-m) writes for the IDT72V2111, where m is the
full offset value. The default setting for this value is stated in the footnote
of Table 2.
See Figure 16, Programmable Almost-Full Flag Timing (IDT Standard and
FWFT Mode), for the relevant timing information.
PAF is synchronous and updated on the rising edge of WCLK.
PROGRAMMABLE ALMOST-EMPTY FLAG (
PAE)
The Programmable Almost-Empty flag (
PAE)willgoLOWwhentheFIFO
reaches the almost-empty condition. In IDT Standard mode, PAE will go LOW
when there are n words or less in the FIFO. The offset “n” is the empty offset
value. The default setting for this value is stated in the footnote of Table 1.
In FWFT mode, the
PAE will go LOW when there are n+1 words or less
in the FIFO. The default setting for this value is stated in the footnote of Table 2.
See Figure 17, Programmable Almost-Empty Flag Timing (IDT Standard
and FWFT Mode), for the relevant timing information.
PAE is synchronous and updated on the rising edge of RCLK.
HALF-FULL FLAG (
HF)
Thisoutputindicatesahalf-fullFIFO.TherisingWCLKedgethatfillstheFIFO
beyondhalf-fullsets
HFLOW.TheflagremainsLOWuntilthedifferencebetween
the write and read pointers becomes less than or equal to half of the total depth
of the device; the rising RCLK edge that accomplishes this condition sets
HF
HIGH.
In IDT Standard mode, if no reads are performed after reset (
MRS or
PRS), HF will go LOW after (D/2 + 1) writes to the FIFO, where D = 262,144
for the IDT72V2101 and 524,288 for the IDT72V2111.
In FWFT mode, if no reads are performed after reset (
MRS or PRS), HF
will go LOW after (D-1/2 + 2) writes to the FIFO, where D = 262,145 for the
IDT72V2101 and 524,289 for the IDT72V2111.
See Figure 18, Half-Full Flag Timing (IDT Standard and FWFT Modes),
for the relevant timing information. Because
HF is updated by both RCLK
and WCLK, it is considered asynchronous.
DATA OUTPUTS (Q0-Q8)
(Q0 - Q8) are data outputs for 9-bit wide data.