IDT7203 IDT [Integrated Device Technology], IDT7203 Datasheet - Page 10

• Manufacturer Part Number: IDT7203
• Description: CMOS ASYNCHRONOUS FIFO 2048 x 9, 4096 x 9, 8192 x 9 and 16384 x 9
• Manufacturer: IDT [Integrated Device Technology]

IDT7203/7204/7205/7206 CMOS ASYNCHRONOUS FIFO
2048 x 9, 4096 x 9, 8192 x 9 and 16384 x 9
OPERATING MODES:
monitored by each system (i.e.
where
used). For additional information, refer to Tech Note 8: Oper-
ating FIFOs on Full and Empty Boundary Conditions and
Tech Note 6: Designing with FIFOs.
Single Device Mode
application requirements are for 2048/4096/8192/16384 words
or less. The IDT7203/7204/7205/7206 is in a Single Device
Configuration when the Expansion In (
grounded (see Figure 12).
Depth Expansion
applications when the requirements are for greater than 2048/
4096/8192/16384 words. Figure 14 demonstrates Depth Ex-
pansion using three IDT7203/7204/7205/7206s. Any depth
can be attained by adding additional IDT7203/7204/7205/
7206s. The IDT7203/7204/7205/7206 operates in the Depth
Expansion mode when the following conditions are met:
1. The first device must be designated by grounding the First
2. All other devices must have
3. The Expansion Out (
4. External logic is needed to generate a composite Full Flag
5. The Retransmit (
FIFOs or FIFO Modules.
A single IDT7203/7204/7205/7206 may be used when the
The IDT7203/7204/7205/7206 can easily be adapted to
For additional information, refer to Tech Note 9: Cascading
Load (
the Expansion In (
(
EF
correct composite
not available in the Depth Expansion Mode.
Care must be taken to assure that the appropriate flag is
FF
s and ORing of all
) and Empty Flag (
W
FL
is used;
) control input.
XI
W
R
EF
RT
XI
is monitored on the device where
FF
) pin of the next device. See Figure 14.
) function and Half-Full Flag (
FF
XO
or
EF
s (i.e. all must be set to generate the
) pin of each device must be tied to
EF
t
). This requires the ORing of all
XIS
). See Figure 14.
FF
FL
is monitored on the device
in the HIGH state.
FIRST PHYSICAL
t
XI
LOCATION
WRITE TO
XI
) control input is
Figure 11. Expansion In
HF
) are
R
is
t
5.04
XIR
USAGE MODES:
Width Expansion
corresponding input control signals of multiple devices. Sta-
tus flags (
Figure 13 demonstrates an 18-bit word width by using two
IDT7203/7204/7205/7206s. Any word width can be attained
by adding additional IDT7203/7204/7205/7206s (Figure 13).
Bidirectional Operation
systems (each system capable of Read and Write operations)
can be achieved by pairing IDT7203/7204/7205/7206s as
shown in Figure 16. Both Depth Expansion and Width Expan-
sion may be used in this mode.
Data Flow-Through
flow-through and write flow-through mode. For the read flow-
through mode (Figure 17), the FIFO permits a reading of a
single word after writing one word of data into an empty FIFO.
The data is enabled on the bus in (t
edge of
until the
bus would go into a three-state mode after t
would have a pulse showing temporary deassertion and then
would be asserted.
permits the writing of a single word of data immediately after
reading one word of data from a full FIFO. The
the
be asserted again in anticipation of a new data word. On the
rising edge of
line must be toggled when
in the FIFO and to increment the write pointer.
Compound Expansion
applied together in a straightforward manner to achieve large
FIFO arrays (see Figure 15).
Word width may be increased simply by connecting the
Applications which require data buffering between two
Two types of flow-through modes are permitted, a read
In the write flow-through mode (Figure 18), the FIFO
The two expansion techniques described above can be
FF
to be deasserted but the
W
R
EF
t
, called the first write edge, and it remains on the bus
XIS
line is raised from LOW-to-HIGH, after which the
MILITARY AND COMMERCIAL TEMPERATURE RANGES
,
FF
W
and
, the new word is loaded in the FIFO. The
FIRST PHYSICAL
HF
READ FROM
LOCATION
) can be detected from any one device.
FF
is not asserted to write new data
W
line being LOW causes it to
WEF
2661 drw 11
+ t
A
RHZ
) ns after the rising
ns. The
R
line causes
EF
10
line
W