IDT72V291L15PFI IDT, Integrated Device Technology Inc, IDT72V291L15PFI Datasheet - Page 11

• Manufacturer Part Number: IDT72V291L15PFI
• Description: IC FIFO SS 32768X36 15NS 64QFP
• Manufacturer: IDT, Integrated Device Technology Inc
• Series: 72Vr

Specifications of IDT72V291L15PFI

• Function: Synchronous
• Memory Size: 1.1M (32K x 36)
• Data Rate: 67MHz
• Access Time: 15ns
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 72V291L15PFI

which timing mode (IDT Standard or FWFT modes) has been selected.
RETRANSMIT OPERATION
accessed again. There are two stages: first, a setup procedure that resets
the read pointer to the first location of memory, then the actual retransmit,
which consists of reading out the memory contents, starting at the beginning
of memory.
edge. REN and WEN must be HIGH before bringing RT LOW. At least
one word, but no more than D - 2 words should have been written into the
FIFO between Reset (Master or Partial) and the time of Retransmit setup.
D = 65,536 for the IDT72V281 and D = 131,072 for the IDT72V291 in IDT
Standard mode.
D = 131,073 for the IDT72V291.
the Retransmit setup by setting EF LOW. The change in level will only be
noticeable if EF was HIGH before setup. During this period, the internal
read pointer is initialized to the first location of the RAM array.
tions may begin starting with the first location in memory. Since IDT
IDT72V281/72V291 3.3V CMOS SUPERSYNC FIFO
65,536 x 9 and 131,072 x 9
The Retransmit operation allows data that has already been read to be
Retransmit setup is initiated by holding RT LOW during a rising RCLK
If IDT Standard mode is selected, the FIFO will mark the beginning of
When EF goes HIGH, Retransmit setup is complete and read opera-
Parallel reading of the offset registers is always permitted regardless of
In FWFT mode, D = 65,537 for the IDT72V281 and
TM
11
Standard mode is selected, every word read including the first word
following Retransmit setup requires a LOW on REN to enable the rising
edge of RCLK. See Figure 11, Retransmit Timing (IDT Standard Mode), for
the relevant timing diagram.
Retransmit setup by setting OR HIGH. During this period, the internal read
pointer is set to the first location of the RAM array.
the contents of the first location appear on the outputs. Since FWFT mode
is selected, the first word appears on the outputs, no LOW on REN is
necessary. Reading all subsequent words requires a LOW on REN to
enable the rising edge of RCLK. See Figure 12, Retransmit Timing (FWFT
Mode), for the relevant timing diagram.
HF and PAF flags begin with the rising edge of RCLK that RT is setup.
PAE is synchronized to RCLK, thus on the second rising edge of RCLK
after RT is setup, the PAE flag will be updated. HF is asynchronous, thus
the rising edge of RCLK that RT is setup will update HF. PAF is
synchronized to WCLK, thus the second rising edge of WCLK that occurs
t
is synchronized to RCLK.
SKEW
If FWFT mode is selected, the FIFO will mark the beginning of the
When OR goes LOW, Retransmit setup is complete; at the same time,
For either IDT Standard mode or FWFT mode, updating of the PAE,
after the rising edge of RCLK that RT is setup will update PAF. RT
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES