IDT7204 IDT [Integrated Device Technology], IDT7204 Datasheet - Page 9

• Manufacturer Part Number: IDT7204
• Description: CMOS ASYNCHRONOUS FIFO
• Manufacturer: IDT [Integrated Device Technology]

OPERATING MODES:
each system (i.e. FF is monitored on the device where W is used; EF is monitored
on the device where R is used). For additional information on the IDT7203/7204/
7205/7206/7207, refer to Tech Note 8: Operating FIFOs on Full and Empty
Boundary Conditions and Tech Note 6: Designing with FIFOs.
Single Device Mode
application requirements are for 2,048/4,096/8,192/16,384/32,768/65,536 words
or less. These FIFOs are in a Single Device Configuration when the Expansion
In (XI) control input is grounded (see Figure 12).
Depth Expansion
ments are for greater than 2,048/4,096/8,192/16,384/32,768/65,536 words.
Figure 14 demonstrates Depth Expansion using three IDT7203/7204/7205/
7206/7207/7208s. Any depth can be attained by adding additional IDT7203/
XO
HF
W
IDT7203/7204/7205/7206/7207/7208 CMOS ASYNCHRONOUS FIFO
2,048 x 9, 4,096 x 9, 8,192 x 9, 16,384 x 9, 32,768 x 9 and 65,536 x 9
XI
W
R
R
W
R
A single IDT7203/7204/7205/7206/7207/7208 may be used when the
These FIFOs can easily be adapted to applications when the require-
Care must be taken to assure that the appropriate flag is monitored by
t
HALF-FULL OR LESS
t
XOL
LAST PHYSICAL
XIS
LOCATION
WRITE TO
t
XI
FIRST PHYSICAL
LOCATION
WRITE TO
t
XOH
t
WHF
Figure 9. Half-Full Flag Timing
t
XIR
Figure 10. Expansion Out
Figure 11. Expansion In
t
XOL
MORE THAN HALF-FULL
9
LAST PHYSICAL
7204/7205/7206/7207/7208s. These devices operate in the Depth Expansion
mode when the following conditions are met:
1. The first device must be designated by grounding the First Load (FL) control
2. All other devices must have FL in the HIGH state.
3. The Expansion Out (XO) pin of each device must be tied to the Expansion
4. External logic is needed to generate a composite Full Flag (FF) and Empty
5. The Retransmit (RT) function and Half-Full Flag (HF) are not available in
Tech Note 9: Cascading FIFOs or FIFO Modules.
t
XIS
READ FROM
LOCATION
input.
In (XI) pin of the next device. See Figure 14.
Flag (EF). This requires the ORing of all EFs and ORing of all FFs (i.e. all
must be set to generate the correct composite FF or EF). See Figure 14.
the Depth Expansion Mode.
For additional information on the IDT7203/7204/7205/7206/7207, refer to
FIRST PHYSICAL
READ FROM
LOCATION
COMMERCIAL, INDUSTRIAL AND MILITARY
t
XOH
t
RHF
HALF-FULL OR LESS
TEMPERATURE RANGES
APRIL 3, 2006
2661 drw11
2661 drw12
2661 drw13