Datasheet
CY7C420, CY7C421 CY7C424,
CY7C425 CY7C428, CY7C429
Cascadable 2K x 9 FIFO
The CY7C420/CY7C421, CY7C424/CY7C425, and CY7C428/CY7C429 are first-in first-out (FIFO)
memories offered in 600-mil wide and 300-mil wide packages. They are, respectively, 512, 1,024,
and 2,048 words by 9-bitswide. EachFIFO memory is organized such that the data is read in the
same sequential order that it was written. Full and Empty flags are provided to prevent overrun
and underrun. Three additional pins are also provided to facilitate unlimited expansion in width,
depth, or both. The depth expansion technique steers the control signals from one device to
another
in parallel, thus eliminating the serial addition of propagation delays, so that throughput is not
reduced Data is steered in a similar manner.
Rochester Electronics
Manufactured Components
Rochester branded components are
manufactured using either die/wafers
purchased from the original suppliers
or Rochester wafers recreated from the
original IP. All re-creations are done with
the approval of the Original Component
Manufacturer (OCM).
Parts are tested using original factory
test programs or Rochester developed
test solutions to guarantee product
meets or exceeds the OCM data sheet.
Quality Overview
• ISO-9001
• AS9120 certification
• Qualified Manufacturers List (QML) MIL-PRF-35835
• Class Q Military
• Class V Space Level
• Qualified Suppliers List of Distributors (QSLD)
• Rochester is a critical supplier to DLA and
meets all industry and DLA standards.
Rochester Electronics, LLC is committed to supplying
products that satisfy customer expectations for
quality and are equal to those originally supplied by
industry manufacturers.
The original manufacturer’s datasheet accompanying this document reflects the performance
and specifications of the Rochester manufactured version of this device. Rochester Electronics
guarantees the performance of its semiconductor products to the original OCM specifications.
‘Typical’ values are for reference purposes only. Certain minimum or maximum ratings may be
based on product characterization, design, simulation, or sample testing.
FOR REFERENCE ONLY
© 2019 Rochester Electronics, LLC. All Rights Reserved 05032019
To learn more, please visit www.rocelec.com
• 2589662 0010631 690 •cYP CY7C420, CY7C421
CY7C424, CY7C425
CYPRESS SEMICONDUCTOR
--
65E D
Features
Cascadable 512 x 9 FIFO
Cascadable 1K x 9 FIFO
Cascadable 2K x 9 FIFO
33.3 MHz. The write operation occurs
when the write (W) signal is LOW. Read
occurswhenread(R) goes LOW. The nine
data outputs go to the high-impedance
state when R is IDGR
• TIL compatible
• Three-state outputs
• Pin compatible and functional
equivalent to IDT7201, IDT7202, and
IDT7203
• 512 X 91 11024 X 9, 21048 X 9 FIFO
buffer memocy
• Dual-port RAM cell
• Asynchronous read/write
• fflgh-speed 33.3-MHz read/write
independent of depth/width
• Low operating power
-Ice (mBL)= 142 mA
(commercial)
-Ice (max.)= 147 mA (military)
•
•
•
•
•
CY7C428, CY7C429
CYPRESS
SEMICONDUCTOR
Functional Description
A Half Full (HF) output flag is provided
The CY7C420/CY7C421, CY7C424/ that is valid in the standalone andwidth ex
CY7C425, and CY7C428/CY7C429 are pansion configurations. In the depth ex
first-in fust-out (FIFO) memories offered pansion configuration, this pin provides
in 600-mil wide and 300-mil wide pack the expansion out (XO)information that is
ages. They are, respectively, 512, 1,024, used to tell the nextFIFO that itwill be ac
and 2,048words by 9-bitswide.EachFIFO tivated.
memory is organized such that the data is
read in the same sequential order that it In the standalone and width expansion
was written. Full and Empty flags are pro configurations, a LOW on the retransmit
vided to prevent overrun and underrun. (RI) input causes theFIFOs to retransmit
Three additional pins are also provided to the data. Read enable(R) and write enable
facilitate unlimited expansion in width, (W) must both be IDGH during retrans
depth, or both. The depth expansion tech mit, and then R is used to access the data.
nique steers the control signals from one The CY7C420, CY7C421, CY7C424,
device to another in parallel, thus eliminat CY7C425, CY7C428, and CY7C429 are
ing the serial addition of propagation de fabricated using an advanced 0.8-micron
lays, so that throughput is not reduced N-wellCMOS technology. JnputESDpro
Data is steered in a similar manner.
tection is greater than 2000V and latch-up
The read and write operations may be is prevented by careful layout, guard rings,
asynchronous; each can occur at a rate of and a substrate bias generator.
Half Full flag in standalone
Empty and Full flags
Retransmit in standalone
Expandable in width and depth
Parallel cascade minimizes
bubble-through
• 5V ± 10% supply
• 300-mil DIP packaging
• 300-mil SOJ packaging
Logic Block Diagram
Pin Configurations
DATA INPUTS
(Do-Da)
PLCC/LCC
DIP
Top View
Top View
d., d01::: � >'d ov oin
w
WRITE
CONTROL
D2
Do
0-,
D1
READ
POINTER
NG
"FORT
El'
a,
XO/HF
°"
a,
NC
a,
DATA OUTPUTS
(Oo-Oa)
li
E�\'c
IMI
"FORT
i---+---+J--r►FI'
L___
E'
o
::::::::::::.::::.::::.;:LEXrtGs:1h_NJ----XO/RI'
-=::
C420-1
5-26
cf' cJ"