72V3640L15PF IDT, 72V3640L15PF Datasheet - Page 19
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72V3640L15PF
Manufacturer Part Number
72V3640L15PF
Description
FIFO
Manufacturer
IDT
Datasheet
1.72V3690L6PFG.pdf
(46 pages)
Specifications of 72V3640L15PF
Part # Aliases
IDT72V3640L15PF
SIGNAL DESCRIPTION
INPUTS:
DATA IN (D
(D
CONTROLS:
MASTER RESET ( MRS )
state. This operation sets the internal read and write pointers to the first location
of the RAM array. PAE will go LOW, PAF will go HIGH, and HF will go HIGH.
along with EF and FF are selected. EF will go LOW and FF will go HIGH. If
FWFT/SI is HIGH, then the First Word Fall Through mode (FWFT), along with
IR and OR, are selected. OR will go HIGH and IR will go LOW.
during the Master Reset cycle.
Reset is required after power up, before a write operation can take place. MRS
is asynchronous.
PARTIAL RESET ( PRS )
state. As in the case of the Master Reset, the internal read and write pointers
are set to the first location of the RAM array, PAE goes LOW, PAF goes HIGH,
and HF goes HIGH.
or First Word Fall Through, that mode will remain selected. If the IDT Standard
mode is active, then FF will go HIGH and EF will go LOW. If the First Word Fall
Through mode is active, then OR will go HIGH, and IR will go LOW.
unchanged. The programming method (parallel or serial) currently active at
the time of Partial Reset is also retained. The output register is initialized to all
zeroes. PRS is asynchronous.
operation, when reprogramming programmable flag offset settings may not be
convenient.
ASYNCHRONOUS WRITE (ASYW)
mode of operation. If during Master Reset the ASYW input is LOW, then
Asynchronous operation of the write port will be selected. During Asynchronous
operation of the write port the WCLK input becomes WR input, this is the
Asynchronous write strobe input. A rising edge on WR will write data present
on the Dn inputs into the FIFO. (WEN must be tied LOW when using the write
port in Asynchronous mode).
(FF) operates in an asynchronous manner, that is, the full flag will be updated
based in both a write operation and read operation. Note, if Asynchronous mode
is selected, FWFT is not permissable. Refer to Figures 23, 24, 27 and 28 for
relevant timing and operational waveforms.
IDT72V3640/50/60/70/80/90 3.3V HIGH DENSITY SUPERSYNC II
1,024 x 36, 2,048 x 36, 4,096 x 36, 8,192 x 36, 16,384 x 36 and 32,768 x 36
0
Data inputs for 36-bit wide data (D
A Master Reset is accomplished whenever the MRS input is taken to a LOW
All control settings such as OW, IW, BM, BE, RM, PFM and IP are defined
During a Master Reset, the output register is initialized to all zeroes. A Master
See Figure 5, Master Reset Timing, for the relevant timing diagram.
A Partial Reset is accomplished whenever the PRS input is taken to a LOW
Whichever mode is active at the time of Partial Reset, IDT Standard mode
Following Partial Reset, all values held in the offset registers remain
A Partial Reset is useful for resetting the device during the course of
See Figure 6, Partial Reset Timing, for the relevant timing diagram.
The write port can be configured for either Synchronous or Asynchronous
When the write port is configured for Asynchronous operation the full flag
- D
If FWFT/SI is LOW during Master Reset then the IDT Standard mode,
17
) or data inputs for 9-bit wide data (D
0
- D
n
)
0
- D
35
), data inputs for 18-bit wide data
0
- D
8
).
TM
19
36-BIT FIFO
ASYNCHRONOUS READ (ASYR)
mode of operation. If during a Master Reset the ASYR input is LOW, then
Asynchronous operation of the read port will be selected. During Asynchronous
operation of the read port the RCLK input becomes RD input, this is the
Asynchronous read strobe input. A rising edge on RD will read data from the
FIFO via the output register and Qn port. (REN must be tied LOW during
Asynchronous operation of the read port).
asynchronous manner.
must be operating on IDT standard mode, FWFT mode is not permissible if the
read port is Asynchronous. The Empty Flag (EF) operates in an Asynchronous
manner, that is, the empty flag will be updated based on both a read operation
and a write operation. Refer to figures 25, 26, 27 and 28 for relevant timing and
operational waveforms.
RETRANSMIT ( RT )
accessed again. There are 2 modes of Retransmit operation, normal latency
and zero latency. There are two stages to Retransmit: 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 the memory.
REN and WEN must be HIGH before bringing RT LOW. When zero latency
is utilized, REN does not need to be HIGH before bringing RT LOW.
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.
may begin starting with the first location in memory. Since IDT 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.
setup by setting OR HIGH. During this period, the internal read pointer is set
to the first location of the RAM array.
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.
Retransmit Mode (RM) pin during a Master Reset. This can be applied to both
IDT Standard mode and FWFT mode.
FIRST WORD FALL THROUGH/SERIAL IN (FWFT/SI)
input determines whether the device will operate in IDT Standard mode or First
Word Fall Through (FWFT) mode.
will be selected. This mode uses the Empty Flag (EF) to indicate whether or
The read port can be configured for either Synchronous or Asynchronous
The OE input provides three-state control of the Qn output bus, in an
When the read port is configured for Asynchronous operation the device
The Retransmit operation allows data that has already been read to be
Retransmit setup is initiated by holding RT LOW during a rising RCLK edge.
If IDT Standard mode is selected, the FIFO will mark the beginning of the
When EF goes HIGH, Retransmit setup is complete and read operations
If FWFT mode is selected, the FIFO will mark the beginning of the Retransmit
When OR goes LOW, Retransmit setup is complete; at the same time, the
In Retransmit operation, zero latency mode can be selected using the
This is a dual purpose pin. During Master Reset, the state of the FWFT/SI
If, at the time of Master Reset, FWFT/SI is LOW, then IDT Standard mode
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OCTOBER 22, 2008