72T36115L4-4BBG Integrated Device Technology (Idt), 72T36115L4-4BBG Datasheet - Page 16

• Manufacturer Part Number: 72T36115L4-4BBG
• Description: FIFO Mem Async/Sync Dual Depth/Width Uni-Dir 128K x 36 240-Pin BGA
• Manufacturer: Integrated Device Technology (Idt)

Specifications of 72T36115L4-4BBG

• Package: 240BGA
• Configuration: Dual
• Bus Directional: Uni-Directional
• Density: 4.5 Mb
• Organization: 128Kx36
• Data Bus Width: 36 Bit
• Timing Type: Asynchronous|Synchronous
• Expansion Type: Depth|Width
• Typical Operating Supply Voltage: 2.5 V
• Operating Temperature: 0 to 70 °C

FUNCTIONAL DESCRIPTION
TIMING MODES: IDT STANDARD vs FIRST WORD FALL THROUGH
(FWFT) MODE
ing modes of operation: IDT Standard mode or First Word Fall Through
(FWFT) mode. The selection of which mode will operate is determined during
Master Reset, by the state of the FWFT/SI input.
will be selected. This mode uses the Empty Flag (EF) to indicate whether or not
there are any words present in the FIFO. It also uses the Full Flag function (FF)
to indicate whether or not the FIFO has any free space for writing. In IDT
Standard mode, every word read from the FIFO, including the first, must be
requested using the Read Enable (REN) and RCLK.
selected. This mode uses Output Ready (OR) to indicate whether or not there
is valid data at the data outputs (Q
whether or not the FIFO has any free space for writing. In the FWFT mode, the
first word written to an empty FIFO goes directly to Q
edges, REN = LOW is not necessary. Subsequent words must be accessed
using the Read Enable (REN) and RCLK.
on which timing mode is in effect.
IDT STANDARD MODE
manner outlined in Table 3. To write data into to the FIFO, Write Enable (WEN)
must be LOW. Data presented to the DATA IN lines will be clocked into the FIFO
on subsequent transitions of the Write Clock (WCLK). After the first write is
performed, the Empty Flag (EF) will go HIGH. Subsequent writes will continue
to fill up the FIFO. The Programmable Almost-Empty flag (PAE) will go HIGH
after n + 1 words have been loaded into the FIFO, where n is the empty offset
value. The default setting for these values are stated in the footnote of Table 2.
This parameter is also user programmable. See section on Programmable Flag
Offset Loading.
operations were taking place, the Half-Full flag (HF) would toggle to LOW once
the 513rd word for IDT72T3645, 1,025th word for IDT72T3655, 2,049th word
for IDT72T3665, 4,097th word for IDT72T3675, 8,193th word for the
IDT72T3685, 16,385th word for the IDT72T3695, 32,769th word for the
IDT72T36105, 65,537th word for the IDT72T36115 and 131,073rd word for
the IDT72T36125, respectively was written into the FIFO. Continuing to write
data into the FIFO will cause the Programmable Almost-Full flag (PAF) to go
LOW. Again, if no reads are performed, the PAF will go LOW after (1,024-m)
writes for the IDT72T3645, (2,048-m) writes for the IDT72T3655, (4,096-m)
writes for the IDT72T3665, (8,192-m) writes for the IDT72T3675, (16,384-m)
writes for the IDT72T3685, (32,768-m) writes for the IDT72T3695, (65,536-m)
writes for the IDT72T36105, (131,072-m) writes for the IDT72T36115 and
(262,144-m) writes for the IDT72T36125. The offset “m” is the full offset value.
The default setting for these values are stated in the footnote of Table 2. This
parameter is also user programmable. See section on Programmable Flag
Offset Loading.
operations. If no reads are performed after a reset, FF will go LOW after D writes
to the FIFO. D = 1,024 writes for the IDT72T3645, 2,048 writes for the
IDT72T3655, 4,096 writes for the IDT72T3665, 8,192 writes for the IDT72T3675,
16,384 writes for the IDT72T3685, 32,768 writes for the IDT72T3695, 65,536
writes for the IDT72T36105, 131,072 writes for the IDT72T36115 and 262,144
IDT72T3645/55/65/75/85/95/105/115/125 2.5V TeraSync™ ™ ™ ™ ™ 36-BIT FIFO
1K x 36, 2K x 36, 4K x 36, 8K x 36, 16K x 36, 32K x 36, 64K x 36, 128K x 36 and 256K x 36
The IDT72T3645/55/65/75/85/95/105/115/125 support two different tim-
Various signals, both input and output signals operate differently depending
In this mode, the status flags, FF, PAF, HF, PAE, and EF operate in the
If one continued to write data into the FIFO, and we assumed no read
When the FIFO is full, the Full Flag (FF) will go LOW, inhibiting further write
If, at the time of Master Reset, FWFT/SI is LOW, then IDT Standard mode
If, at the time of Master Reset, FWFT/SI is HIGH, then FWFT mode will be
n)
. It also uses Input Ready (IR) to indicate
n
after three RCLK rising
16
writes for the IDT72T36125, respectively.
Subsequent read operations will cause PAF and HF to go HIGH at the conditions
described in Table 3. If further read operations occur, without write operations,
PAE will go LOW when there are n words in the FIFO, where n is the empty
offset value. Continuing read operations will cause the FIFO to become empty.
When the last word has been read from the FIFO, the EF will go LOW inhibiting
further read operations. REN is ignored when the FIFO is empty.
register-buffered outputs.
11, 12, 13 and 18.
FIRST WORD FALL THROUGH MODE (FWFT)
manner outlined in Table 4. To write data into to the FIFO, WEN must be LOW.
Data presented to the DATA IN lines will be clocked into the FIFO on subsequent
transitions of WCLK. After the first write is performed, the Output Ready (OR)
flag will go LOW. Subsequent writes will continue to fill up the FIFO. PAE will go
HIGH after n + 2 words have been loaded into the FIFO, where n is the empty
offset value. The default setting for these values are stated in the footnote of
Table 2. This parameter is also user programmable. See section on Program-
mable Flag Offset Loading.
operations were taking place, the HF would toggle to LOW once the 514th word
for the IDT72T3645, 1,026th word for the IDT72T3655, 2,050th word for the
IDT72T3665, 4,098th word for the IDT72T3675, 8,194th word for the
IDT72T3685, 16,386th word for the IDT72T3695, 32,770th word for the
IDT72T36105, 65,538th word for the IDT72T36115 and 131,074th word for
the IDT72T36125, respectively was written into the FIFO. Continuing to write
data into the FIFO will cause the PAF to go LOW. Again, if no reads are
performed, the PAF will goLOW after (1,025-m) writes for the IDT72T3645,
(2,049-m) writes for the IDT72T3655, (4,097-m) writes for the IDT72T3665
and (8,193-m) writes for the IDT72T3675, (16,385-m) writes for the IDT72T3685,
(32,769-m) writes for the IDT72T3695, (65,537-m) writes for the IDT72T36105,
(131,073-m) writes for the IDT72T36115 and (262,145-m) writes for the
IDT72T36125, where m is the full offset value. The default setting for these values
are stated in the footnote of Table 2.
write operations. If no reads are performed after a reset, IR will go HIGH after
D writes to the FIFO. D = 1,025 writes for the IDT72T3645, 2,049 writes for
the IDT72T3655, 4,097 writes for the IDT72T3665 and 8,193 writes for the
IDT72T3675,16,385 writes for the IDT72T3685, 32,769 writes for the
IDT72T3695, 65,537 writes for the IDT72T36105, 131,073 writes for the
IDT72T36115 and 262,145 writes for the IDT72T36125, respectively. Note
that the additional word in FWFT mode is due to the capacity of the memory plus
output register.
Subsequent read operations will cause the PAF and HF to go HIGH at the
conditions described in Table 4. If further read operations occur, without write
operations, the PAE will go LOW when there are n + 1 words in the FIFO, where
n is the empty offset value. Continuing read operations will cause the FIFO to
become empty. When the last word has been read from the FIFO, OR will go
HIGH inhibiting further read operations. REN is ignored when the FIFO is empty.
buffered, and the IR flag output is double register-buffered.
16 and 19.
If the FIFO is full, the first read operation will cause FF to go HIGH.
When configured in IDT Standard mode, the EF and FF outputs are double
Relevant timing diagrams for IDT Standard mode can be found in Figure
In this mode, the status flags, IR, PAF, HF, PAE, and OR operate in the
If one continued to write data into the FIFO, and we assumed no read
When the FIFO is full, the Input Ready (IR) flag will go HIGH, inhibiting further
If the FIFO is full, the first read operation will cause the IR flag to go LOW.
When configured in FWFT mode, the OR flag output is triple register-
Relevant timing diagrams for FWFT mode can be found in Figure 14, 15,
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FEBRUARY 4, 2009