1OCTOBER 2008
CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
IDT7200L
IDT7201LA
IDT7202LA
IDT and the IDT logo are registered trademarks of Integrated Device Technology, Inc.
COMMERCIAL, INDUSTRIAL AND MILITARY TEMPERATURE RANGES
©2008 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. DSC-2679/12
FEATURES:
••
••
•First-In/First-Out dual-port memory
••
••
•256 x 9 organization (IDT7200)
••
••
•512 x 9 organization (IDT7201)
••
••
•1,024 x 9 organization (IDT7202)
••
••
•Low power consumption
— Active: 440mW (max.)
—Power-down: 28mW (max.)
••
••
•Ultra high speed—12ns access time
••
••
•Asynchronous and simultaneous read and write
••
••
•Fully expandable by both word depth and/or bit width
••
••
•Pin and functionally compatible with 720X family
••
••
•Status Flags: Empty, Half-Full, Full
••
••
•Auto-retransmit capability
••
••
•High-performance CEMOS™ technology
••
••
•Military product compliant to MIL-STD-883, Class B
••
••
•Standard Military Drawing #5962-87531, 5962-89666, 5962-89863
and 5962-89536 are listed on this function
••
••
•Dual versions available in the TSSOP package. For more informa-
tion, see IDT7280/7281/7282 data sheet
IDT7280 = 2 x IDT7200
IDT7281 = 2 x IDT7201
IDT7282 = 2 x IDT7202
DESCRIPTION:
The IDT7200/7201/7202 are dual-port memories that load and empty data
on a first-in/first-out basis. The devices use Full and Empty flags to prevent data
overflow and underflow and expansion logic to allow for unlimited expansion
capability in both word size and depth.
The reads and writes are internally sequential through the use of ring
pointers, with no address information required to load and unload data. Data
is toggled in and out of the devices through the use of the Write (W) and Read
(R) pins.
The devices utilize a 9-bit wide data array to allow for control and parity bits
at the user’s option. This feature is especially useful in data communications
applications where it is necessary to use a parity bit for transmission/reception
error checking. It also features a Retransmit (RT) capability that allows for reset
of the read pointer to its initial position when RT is pulsed LOW to allow for
retransmission from the beginning of data. A Half-Full Flag is available in the
single device mode and width expansion modes.
These FIFOs are fabricated using IDT’s high-speed CMOS technology.
They are designed for those applications requiring asynchronous and
simultaneous read/writes in multiprocessing and rate buffer applications.
Military grade product is manufactured in compliance with the latest revision of
MIL-STD-883, Class B.
FUNCTIONAL BLOCK DIAGRAM
WWRITE
CONTROL
READ
CONTROL
R
FLAG
LOGIC
EXPANSION
LOGIC
XI
WRITE
POINTER
RAM
ARRAY
256 x 9
512 x 9
1,024 x 9
READ
POINTER
DATA INPUTS
RESET
LOGIC
THREE-
STATE
BUFFERS
DATA OUTPUTS
EF
FF
XO/HF
RS
FL/RT
(D
0
-D
8
)
2679 drw 01
(Q
0
-Q
8
)
••
••
•Industrial temperature range (–40oC to +85oC) is available
(plastic packages only)
••
••
•Green parts available, see ordering information
2
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
PIN CONFIGURATIONS
RECOMMENDED DC OPERATING
CONDITIONS
Symbol Parameter Min. Typ. Max. Unit
VCC Supply Voltage 4.5 5.0 5.5 V
Commercial/Industrial/Military
GND Supply Voltage 0 0 0 V
VIH(1) Input High Voltage Com'l/Ind'l 2.0 — — V
VIH(1) Input High Voltage Military 2.2 — — V
VIL(2) Input Low Voltage — — 0.8 V
Commercial/Industrial/Military
TAOperating Temperature Commercial 0 — 70 °C
TAOperating Temperature Industrial –40 — 85 °C
TAOperating Temperature Military –55 — 125 °C
NOTES:
1. For RT/RS/XI input, VIH = 2.6V (commercial).
For RT/RS/XI input, VIH = 2.8V (military).
2. 1.5V undershoots are allowed for 10ns once per cycle.
ABSOLUTE MAXIMUM RATINGS
Symbol Rating Com’l & Ind'l Mil. Unit
VTERM Terminal Voltage –0.5 to +7.0 –0.5 to +7.0 V
with Respect
to GND
TSTG Storage –55 to +125 –65 to +155 °C
Temperature
IOUT DC Output –50 to +50 –50 to +50 mA
Current
NOTE:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation of
the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
Reference Order
Package Type Identifier Code
PLASTIC DIP(1) P28-1 P
PLASTIC THIN DIP P28-2 TP
CERDIP(1) D28-1 D
THIN CERDIP D28-3 TD
SOIC SO28-3 SO
TOP VIEW
Reference Order
Package Type Identifier Code
LCC(1) L32- 1 L
PLCC J32-1 J
TOP VIEW
NOTE:
1. The 600-mil-wide DIP (P28-1 and D28-1) and LCC are not available for the IDT7200.
W
D8
VCC
D4
1
2
28
27
D3D5326
D2D6425
D1D7524
D0FL/RT623
XI RS
722
FF EF
821
Q0XO/HF920
Q1Q710 19
Q2Q611 18
Q3Q512 17
Q8Q413 16
GND R
14 15
2679 drw 02a
D
2
5
D
1
6
D
0
7
XI 8
FF 9
Q
0
10
Q
1
11
NC 12
Q
2
13
D
6
D
7
NC
FL/RT
RS
EF
XO/HF
Q
7
Q
6
29
28
27
26
25
24
23
22
21
43 2 132 31 30
14 15 16 17 18 19 20
Q
3
Q
8
GND
NC
R
Q
4
Q
5
D
3
D
8
W
NC
V
CC
D
4
D
5
INDEX
2679 drw 02b
3
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
DC ELECTRICAL CHARACTERISTICS
(Commercial: VCC = 5V ± 10%, TA = 0oC to +70oC; Industrial: VCC = 5V ± 10%, TA = –40oC to +85oC; Military: VCC = 5V ± 10%, TA = –55oC to +125oC)
IDT7200L IDT7200L
IDT7201LA IDT7201LA
IDT7202LA IDT7202LA
Com'l & Ind'l(1) Military(2)
tA = 12, 15, 20, 25, 35, 50 ns tA = 20, 30, 50, 80 ns
Symbol Parameter Min. Max. Min. Max. Unit
ILI(3) Input Leakage Current (Any Input) –1 1 –10 10 µA
ILO(4) Output Leakage Current –10 10 –10 10 µA
VOH Output Logic “1” Voltage IOH = –2mA 2.4 — 2.4 — V
VOL Output Logic “0” Voltage IOL = 8mA — 0.4 — 0.4 V
ICC1(5,6,7) Active Power Supply Current — 80 — 100 mA
ICC2(5,8) Standby Current (R=W=RS=FL/RT=VIH)—5—15mA
NOTES:
1. Industrial temperature range product for the 15ns and 25 ns speed grades are available as a standard device.
2. Military speed grades of 50ns and 80ns are only available for the IDT7201LA.
3. Measurements with 0.4 ≤ VIN ≤ VCC.
4. R ≥ VIH, 0.4 ≤ VOUT ≤ VCC.
5. Tested with outputs open (IOUT = 0).
6. Tested at f = 20 MHz.
7 . Typical ICC1 = 15 + 2*fS + 0.02*CL*fS (in mA) with VCC = 5V, TA = 25°C, fS = WCLK frequency = RCLK frequency (in MHz, using TTL levels), data switching at fS/2, CL = capacitive
load (in pF).
8. All Inputs = VCC - 0.2V or GND + 0.2V.
AC TEST CONDITIONS
Input Pulse Levels GND to 3.0V
Input Rise/Fall Times 5ns
Input Timing Reference Levels 1.5V
Output Reference Levels 1.5V
Output Load See Figure 1
Symbol Parameter Condition Max. Unit
CIN Input Capacitance VIN = 0V 8 pF
COUT Output Capacitance VOUT = 0V 8 pF
NOTE:
1. Characterized values, not currently tested.
CAPACITANCE (TA = +25°C, f = 1.0 MHz)
or equivalent circuit
2679 drw 03
30pF*
1.1K
5V
TO
OUTPUT
PIN
680Ω
Figure 1. Output Load
* Includes scope and jig capacitances.
4
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
Commercial Com'l & Ind'l(2) Com'l & Mil. Com'l & Ind'l(2)
IDT7200L12 IDT7200L15 IDT7200L20 IDT7200L25
IDT7201LA12 IDT7201LA15 IDT7201LA20 IDT7201LA25
IDT7202LA12 IDT7202LA15 IDT7202LA20 IDT7202LA25
Symbol Parameter Min. Max. Min. Max. Min. Max. Min. Max. Unit
tSShift Frequency — 50 — 40 — 33.3 — 28.5 MHz
tRC Read Cycle Time 20 — 25 — 30 — 3 5 — ns
tAAccess Time — 12 — 15 — 20 — 25 ns
tRR Read Recovery Time 8 — 10 — 10 — 10 — ns
tRPW Read Pulse Width(3) 12 — 15 — 20 — 25 — ns
tRLZ Read Pulse Low to Data Bus at Low Z(4) 3—3—3—3—ns
tWLZ Write Pulse High to Data Bus at Low Z(4,5) 5—5—5—5—ns
tDV Data Valid from Read Pulse High 5 — 5 — 5 — 5 — ns
tRHZ Read Pulse High to Data Bus at High Z(4) — 12 — 15 — 15 — 18 ns
tWC Write Cycle Time 20 — 25 — 30 — 3 5 — ns
tWPW Write Pulse Width(3) 12 — 15 — 20 — 25 — ns
tWR Write Recovery Time 8 — 10 — 10 — 10 — ns
tDS Data Set-up Time 9 — 11 — 12 — 15 — ns
tDH Data Hold Time 0 — 0 — 0 — 0 — ns
tRSC Reset Cycle Time 20 — 25 — 30 — 3 5 — ns
tRS Reset Pulse Width(3) 12 — 15 — 20 — 25 — ns
tRSS Reset Set-up Time(4) 12 — 15 — 20 — 25 — ns
tRSR Reset Recovery Time 8 — 10 — 10 — 10 — ns
tRTC Retransmit Cycle Time 20 — 25 — 30 — 35 — ns
tRT Retransmit Pulse Width(3) 12 — 15 — 20 — 25 — ns
tRTS Retransmit Set-up Time(4) 12 — 15 — 20 — 25 — ns
tRTR Retransmit Recovery Time 8 — 10 — 10 — 10 — ns
tEFL Reset to Empty Flag Low — 1 2 — 25 — 30 — 35 ns
tHFH,FFH Reset to Half-Full and Full Flag High — 17 — 25 — 30 — 35 ns
tRTF Retransmit Low to Flags Valid — 20 — 25 — 30 — 35 ns
tREF Read Low to Empty Flag Low — 1 2 — 1 5 — 2 0 — 2 5 ns
tRFF Read High to Full Flag High — 1 4 — 15 — 20 — 25 ns
tRPE Read Pulse Width after EF High 12 — 15 — 20 — 25 — ns
tWEF Write High to Empty Flag High — 1 2 — 15 — 20 — 25 ns
tWFF Write Low to Full Flag Low — 1 4 — 15 — 20 — 25 ns
tWHF Write Low to Half-Full Flag Low — 1 7 — 25 — 30 — 35 ns
tRHF Read High to Half-Full Flag High — 17 — 25 — 30 — 35 ns
tWPF Write Pulse Width after FF High 12 — 15 — 20 — 25 — ns
tXOL Read/Write to XO Low — 12 — 15 — 20 — 25 ns
tXOH Read/Write to XO High — 12 — 15 — 20 — 25 ns
tXI XI Pulse Width(3) 12 — 15 — 20 — 25 — ns
tXIR XI Recovery Time 8 — 1 0 — 10 — 10 — ns
tXIS XI Set-up Time 8 — 10 — 10 — 10 — ns
NOTES:
1. Timings referenced as in AC Test Conditions.
2 . Industrial temperature range product for 15ns and 25ns speed grades are available as a standard device.
3. Pulse widths less than minimum value are not allowed.
4. Values guaranteed by design, not currently tested.
5 . Only applies to read data flow-through mode
AC ELECTRICAL CHARACTERISTICS(1)
(Commercial: VCC = 5V ± 10%, TA = 0°C to +70°C; Industrial: VCC = 5V ± 10%, TA = –40°C to +85°C; Military: VCC = 5V ± 10%, TA = –55°C to +125°C)
5
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
Military Commercial Com'l & Mil.(2) Military(2)
IDT7200L30 IDT7200L35 IDT7200L50
IDT7201LA30 IDT7201LA35 IDT7201LA50
IDT7202LA30 IDT7202LA35 IDT7202LA50 IDT7201LA80
Symbol Parameter Min. Max. Min. Max. Min. Max. Min. Max. Unit
tSShift Frequency — 25 — 22.2 — 15 — 10 MHz
tRC Read Cycle Time 40 — 45 — 65 — 100 — ns
tAAccess Time — 30 — 35 — 50 — 80 ns
tRR Read Recovery Time 10 — 10 — 15 — 20 — ns
tRPW Read Pulse Width(3) 30 — 35 — 50 — 80 — ns
tRLZ Read Pulse Low to Data Bus at Low Z(4) 3—3—3—3—ns
tWLZ Write Pulse High to Data Bus at Low Z(4, 5) 5—5—5—5—ns
tDV Data Valid from Read Pulse High 5 — 5 — 5 — 5 — ns
tRHZ Read Pulse High to Data Bus at High Z(4) —20—20—30—30ns
tWC Write Cycle Time 40 — 4 5 — 65 — 100 — ns
tWPW Write Pulse Width(3) 30 — 35 — 50 — 80 — ns
tWR Write Recovery Time 10 — 10 — 15 — 20 — ns
tDS Data Set-up Time 18 — 18 — 30 — 40 — ns
tDH Data Hold Time 0 — 0 — 5 — 10 — ns
tRSC Reset Cycle Time 40 — 45 — 65 — 100 — ns
tRS Reset Pulse Width(3) 30 — 35 — 50 — 80 — ns
tRSS Reset Set-up Time(4) 30 — 35 — 50 — 80 — ns
tRSR Reset Recovery Time 10 — 10 — 15 — 20 — ns
tRTC Retransmit Cycle Time 40 — 45 — 65 — 100 — ns
tRT Retransmit Pulse Width(3) 30 — 35 — 50 — 80 — ns
tRTS Retransmit Set-up Time(4) 30 — 35 — 50 — 80 — ns
tRTR Retransmit Recovery Time 10 — 10 — 15 — 20 — ns
tEFL Reset to Empty Flag Low — 4 0 — 4 5 — 6 5 — 100 ns
tHFH,FFH Reset to Half-Full and Full Flag High — 40 — 45 — 65 — 100 ns
tRTF Retransmit Low to Flags Valid — 40 — 45 — 65 — 100 ns
tREF Read Low to Empty Flag Low — 3 0 — 3 0 — 4 5 — 6 0 ns
tRFF Read High to Full Flag High — 3 0 — 30 — 45 — 60 ns
tRPE Read Pulse Width after EF High 30 — 35 — 50 — 80 — ns
tWEF Write High to Empty Flag High — 3 0 — 30 — 45 — 60 ns
tWFF Write Low to Full Flag Low — 30 — 30 — 45 — 60 ns
tWHF Write Low to Half-Full Flag Low — 40 — 45 — 65 — 10 0 ns
tRHF Read High to Half-Full Flag High — 40 — 45 — 65 — 100 ns
tWPF Write Pulse Width after FF High 30 — 35 — 50 — 80 — ns
tXOL Read/Write to XO Low —30—35—50—80ns
tXOH Read/Write to XO High — 30 — 35 — 50 — 80 ns
tXI XI Pulse Width(3) 30 — 35 — 50 — 80 — ns
tXIR XI Recovery Time 10 — 1 0 — 1 0 — 10 — ns
tXIS XI Set-up Time 10 — 10 — 15 — 15 — ns
AC ELECTRICAL CHARACTERISTICS(1) (Continued)
(Commercial: VCC = 5V ± 10%, TA = 0°C to +70°C; Industrial: VCC = 5V ± 10%, TA = –40°C to +85°C; Military: VCC = 5V ± 10%, TA = –55°C to +125°C)
NOTES:
1. Timings referenced as in AC Test Conditions
2. Military speed grades of 50ns and 80ns are only available for IDT7201LA.
3. Pulse widths less than minimum value are not allowed.
4. Values guaranteed by design, not currently tested.
5. Only applies to read data flow-through mode.
6
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
Device Mode, this pin acts as the retransmit input. The Single Device Mode is
initiated by grounding the Expansion In (XI).
The IDT7200/7201A/7202A can be made to retransmit data when the
Retransmit Enable control (RT) input is pulsed LOW. A retransmit operation will
set the internal read pointer to the first location and will not affect the write pointer.
Read Enable (R) and Write Enable (W) must be in the HIGH state during
retransmit. This feature is useful when less than 256/512/1,024 writes are
performed between resets. The retransmit feature is not compatible with the
Depth Expansion Mode and will affect the Half-Full Flag (HF), depending on
the relative locations of the read and write pointers.
EXPANSION IN (XI)
This input is a dual-purpose pin. Expansion In (XI) is grounded to indicate
an operation in the single device mode. Expansion In (XI) is connected to
Expansion Out (XO) of the previous device in the Depth Expansion or Daisy
Chain Mode.
OUTPUTS:
FULL FLAG (FF)
The Full Flag (FF) will go LOW, inhibiting further write operation, when the
write pointer is one location less than the read pointer, indicating that the
device is full. If the read pointer is not moved after Reset (RS), the Full-Flag
(FF) will go LOW after 256 writes for IDT7200, 512 writes for the IDT7201A and
1,024 writes for the IDT7202A.
EMPTY FLAG (EF)
The Empty Flag (EF) will go LOW, inhibiting further read operations, when
the read pointer is equal to the write pointer, indicating that the device is
empty.
EXPANSION OUT/HALF-FULL FLAG (XO/HF)
This is a dual-purpose output. In the single device mode, when
Expansion In (XI) is grounded, this output acts as an indication of a half-full
memory.
After half of the memory is filled and at the falling edge of the next write
operation, the Half-Full Flag (HF) will be set LOW and will remain set until the
difference between the write pointer and read pointer is less than or equal
to one half of the total memory of the device. The Half-Full Flag (HF) is then
reset by using rising edge of the read operation.
In the Depth Expansion Mode, Expansion In (XI) is connected to Expansion
Out (XO) of the previous device. This output acts as a signal to the next device
in the Daisy Chain by providing a pulse to the next device when the previous
device reaches the last location of memory.
DATA OUTPUTS (Q0 – Q8)
Data outputs for 9-bit wide data. This data is in a high impedance condition
whenever Read (R) is in a HIGH state.
SIGNAL DESCRIPTIONS
INPUTS:
DATA IN (D0 – D8)
Data inputs for 9-bit wide data.
CONTROLS:
RESET (RS)
Reset is accomplished whenever the Reset (RS) input is taken to a LOW
state. During reset, both internal read and write pointers are set to the first
location. A reset is required after power up before a write operation can take
place. Both the Read Enable (R) and Write Enable (W) inputs must be
in the HIGH state during the window shown in Figure 2, (i.e., tRSS
before the rising edge of RS) and should not change until tRSR after
the rising edge of RS. Half-Full Flag (HF) will be reset to HIGH after
Reset (RS).
WRITE ENABLE (W)
A write cycle is initiated on the falling edge of this input if the Full Flag (FF)
is not set. Data set-up and hold times must be adhered to with respect to the rising
edge of the Write Enable (W). Data is stored in the RAM array sequentially and
independently of any on-going read operation.
After half of the memory is filled and at the falling edge of the next write
operation, the Half-Full Flag (HF) will be set to LOW and will remain set until the
difference between the write pointer and read pointer is less than or equal to
one half of the total memory of the device. The Half-Full Flag (HF) is then reset
by the rising edge of the read operation.
To prevent data overflow, the Full Flag (FF) will go LOW, inhibiting further
write operations. Upon the completion of a valid read operation, the Full
Flag (FF) will go HIGH after tRFF, allowing a valid write to begin. When the FIFO
is full, the internal write pointer is blocked from W, so external changes in W will
not affect the FIFO when it is full.
READ ENABLE (R)
A read cycle is initiated on the falling edge of the Read Enable (R) provided
the Empty Flag (EF) is not set. The data is accessed on a First-In/First-Out basis,
independent of any ongoing write operations. After Read Enable (R) goes
HIGH, the Data Outputs (Q0 – Q8) will return to a high impedance condition until
the next Read operation. When all data has been read from the FIFO, the Empty
Flag (EF) will go LOW, allowing the “final” read cycle but inhibiting further read
operations with the data outputs remaining in a high impedance state. Once a
valid write operation has been accomplished, the Empty Flag (EF) will go HIGH
after tWEF and a valid Read can then begin. When the FIFO is empty, the internal
read pointer is blocked from R so external changes in R will not affect the FIFO
when it is empty.
FIRST LOAD/RETRANSMIT (FL/RT)
This is a dual-purpose input. In the Depth Expansion Mode, this pin is
grounded to indicate that it is the first loaded (see Operating Modes). In the Single
7
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
NOTES:
1. EF, FF, HF may change status during Reset, but flags will be valid at tRSC.
2. W and R = VIH around the rising edge of RS.
Figure 2. Reset
Figure 4. Full Flag From Last Write to First Read
Figure 3. Asynchronous Write and Read Operation
W
RS
R
EF
HF, FF
t
RSC
t
RS
t
RSS
t
RSS
t
RSR
t
EFL
t
HFH ,
t
FFH
2679 drw 04
t
A
R
t
RC
DATA
OUT
VALID DATA
OUT
VALID
t
RPW
t
RLZ
t
DV
t
A
t
RHZ
t
RR
t
WC
t
WR
t
WPW
DATA
IN
VALID DATA
IN
VALID
t
DS
t
DH
Q
0
-Q
8
2679 drw 05
W
D
0
-D
8
LAST WRITE
R
IGNORED
WRITE
FIRST READ ADDITIONAL
READS
W
FF
tWFF tRFF
FIRST
WRITE
2679 drw 06
8
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
LAST READ
R
IGNORED
READ
FIRST WRITE ADDITIONAL
WRITES
W
EF
t
WEF
VALID
t
A
DATA OUT
t
REF
2679 drw 07
FIRST READ
VALID
Figure 5. Empty Flag From Last Read to First Write
Figure 8. Minimum Timing for a Full Flag Coincident Write Pulse
Figure 7. Minimum Timing for an Empty Flag Coincident Read Pulse
Figure 6. Retransmit
tRTC
tRT
tRTS
RT
W,R
HF, EF, FF
tRTR
FLAG VALID
2679 drw 08
tRTF
EF
W
R
tWEF
tRPE
2679 drw 09
FF
R
W
tRFF
tWPF
2679 drw 10
9
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
Figure 9. Half-Full Flag Timing
Figure 10. Expansion Out
Figure 11. Expansion In
OPERATING MODES:
Care must be taken to assure that the appropriate flag is monitored by
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, refer to Tech Note
8: Operating FIFOs on Full and Empty Boundary Conditions and Tech Note
6: Designing with FIFOs.
SINGLE DEVICE MODE
A single IDT7200/7201A/7202A may be used when the application
requirements are for 256/512/1,024 words or less. These devices are in a
Single Device Configuration when the Expansion In (XI) control input is
grounded (see Figure 12).
DEPTH EXPANSION
The IDT7200/7201A/7202A can easily be adapted to applications when
the requirements are for greater than 256/512/1,024 words. Figure 14
demonstrates Depth Expansion using three IDT7200/7201A/7202As. Any
depth can be attained by adding additional IDT7200/7201A/7202As. These
FIFOs 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
input.
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
In (XI) pin of the next device. See Figure 14.
4. External logic is needed to generate a composite Full Flag (FF) and Empty
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.
5. The Retransmit (RT) function and Half-Full Flag (HF) are not available in
the Depth Expansion Mode.
For additional information, refer to Tech Note 9: Cascading FIFOs or
FIFO Modules.
R
W
HF
t
RHF
HALF-FULL OR LESS MORE THAN HALF-FULL
t
WHF
2679 drw 11
HALF-FULL OR LESS
R
W
XO
2679 drw 12
WRITE TO
LAST PHYSICAL
LOCATION
t
XOL
t
XOH
READ FROM
LAST PHYSICAL
LOCATION
t
XOL
t
XOH
W
R
XI
WRITE TO
FIRST PHYSICAL
LOCATION
t
XIS
READ FROM
FIRST PHYSICAL
LOCATION
t
XIS
t
XI
t
XIR
2679 drw 13
10
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
USAGE MODES:
WIDTH EXPANSION
Word width may be increased simply by connecting the corresponding
input control signals of multiple devices. Status flags (EF, FF and HF) can be
detected from any one device. Figure 13 demonstrates an 18-bit word width
by using two IDT7200/7201A/7202As. Any word width can be attained by
adding additional IDT7200/7201A/7202As (Figure 13).
BIDIRECTIONAL OPERATION
Applications which require data buffering between two systems (each
system capable of Read and Write operations) can be achieved by pairing
IDT7200/7201A/7202As as shown in Figure 16. Both Depth Expansion and
Width Expansion may be used in this mode.
DATA FLOW-THROUGH
Two types of flow-through modes are permitted, a read 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 (tWEF + tA) ns after the rising
edge of W, called the first write edge, and it remains on the bus until the R line
is raised from LOW-to-HIGH, after which the bus would go into a three-state
mode after tRHZ ns. The EF line would have a pulse showing temporary
deassertion and then would be asserted.
In the write flow-through mode (Figure 18), the FIFO permits the writing
of a single word of data immediately after reading one word of data from a
full FIFO. The R line causes the FF to be deasserted but the W line being LOW
causes it to be asserted again in anticipation of a new data word. On the rising
edge of W, the new word is loaded in the FIFO. The W line must be toggled
when FF is not asserted to write new data in the FIFO and to increment the write
pointer.
COMPOUND EXPANSION
The two expansion techniques described above can be applied together
in a straightforward manner to achieve large FIFO arrays (see Figure 15).
Figure 13. Block Diagram of 256 x 18, 512 x 18, 1,024 x 18 FIFO Memory Used in Width Expansion Mode
Figure 12. Block Diagram of Single 256 x 9, 512 x 9, 1,024 x 9 FIFO
WRITE (W)
DATA IN (D)
FULL FLAG (FF)
RESET (RS)
9
READ (R)
9
DATA OUT (Q)
EMPTY FLAG (EF)
RETRANSMIT (RT)
EXPANSION IN (XI)
(HF)
IDT
7200/
7201A/
7202A
(HALF-FULL FLAG)
2679 drw 14
IDT
7200/
7201A/
7202A
XI XI
9918
9
18
HF
HF
9
DATA
WRITE (W)
FULL FLAG (FF)
RESET (RS)
(D)
IN
READ (R)
EMPTY FLAG (EF)
RETRANSMIT (RT)
DATA
OUT
(Q)
IDT
7200/
7201A/
7202A
2679 drw 15
11
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
TABLE 1 — RESET AND RETRANSMIT
Single Device Configuration/Width Expansion Mode
Inputs Internal Status Outputs
Mode RS RT XI Read Pointer Write Pointer EF FF HF
Reset 0 X 0 Location Zero Location Zero 0 1 1
Retransmit 1 0 0 Location Zero Unchanged X X X
Read/Write 1 1 0 Increment(1) Increment(1) XXX
NOTE:
1. Pointer will increment if flag is HIGH.
Figure 14. Block Diagram of 768 x 9, 1,536 x 9, 3,072 x 9 FIFO Memory (Depth Expansion)
T ABLE 2 — RESET AND FIRST LOAD TRUTH T ABLE
Depth Expansion/Compound Expansion Mode
Inputs Internal Status Outputs
Mode RS FL XI Read Pointer Write Pointer EF FF
Reset First Device 0 0 (1) Location Zero Location Zero 0 1
Reset All Other Devices 0 1 (1 ) Location Zero Location Zero 0 1
Read/Write 1 X (1) X X X X
NOTE:
1. XI is connected to XO of previous device. See Figure 14. RS = Reset Input, FL/RT = First Load/Retransmit, EF = Empty Flag Output, FF = Full Flag Output,
XI = Expansion Input, HF = Half-Full Flag Output
D
W
IDT
7200/
7201A/
7202A
FF EF
FL
XO
RS
FULL EMPTY
V
CC
R
9
9
9 9
XI
9 Q
IDT
7200/
7201A/
7202A
IDT
7200/
7201A/
7202A
FF EF
FL
XO
XI
FF EF
FL
XO
XI
2678 drw16
12
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
Figure 15. Compound FIFO Expansion
NOTES:
1. For depth expansion block see section on Depth Expansion and Figure 14.
2. For Flag detection see section on Width Expansion and Figure 13.
Figure 16. Bidirectional FIFO Mode
IDT7200/
IDT7201A/
IDT7202A
DEPTH
EXPANSION
BLOCK
R, W, RS
D
0-
D
N
Q
0-
Q
8
IDT7200/
IDT7201A/
IDT7202A
DEPTH
EXPANSION
BLOCK
IDT7200/
IDT7201A/
IDT7202A
DEPTH
EXPANSION
BLOCK
2679 drw 17
D
0-
D
8
D
9-
D
N
D
18-
D
N
D(
N-8)-
D
N
D
9-
D
17
D
(N-8)-
D
N
Q
0-
Q
8
Q
9-
Q
17
Q
9-
Q
17
Q
(N-8)
-Q
n
Q
(N-8)
-Q
n
IDT
7201A
R
B
EF
B
HF
B
W
A
FF
A
W
B
FF
B
SYSTEM A SYSTEM B
Q
B 0-8
D
B 0-8
Q
A 0-8
R
A
HF
A
EF
A
IDT
7200/
7201A/
7202A
D
A 0-8
IDT
7200/
7201A/
7202A
2679 drw 18
13
COMMERCIAL, INDUSTRIAL AND MILITARY
TEMPERATURE RANGES
IDT7201L/7201LA/7202LA CMOS ASYNCHRONOUS FIFO
256 x 9, 512 x 9 and 1,024 x 9
OCTOBER 22, 2008
Figure 17. Read Data Flow-Through Mode
W
DATA
R
t
RPE
IN
EF
DATA
OUT
t
WLZ
t
WEF
t
A
t
REF
DATA VALID
OUT
2679 drw 19
Figure 18. Write Data Flow-Through Mode
R
DATA
W
IN
FF
DATA
OUT
t
DS
t
DH
t
A
t
WFF
t
RFF
t
WPF
DATA
IN
VALID
DATA
OUT
VALID
2679 drw 20
14
CORPORATE HEADQUARTERS for SALES: for Tech Support:
6024 Silver Creek Valley Road 800-345-7015 or 408-284-8200 408-360-1753
San Jose, CA 95138 fax: 408-284-2775 email: FIFOhelp@idt.com
www.idt.com
ORDERING INFORMATION
XXXX
Device Type
XXX
Speed
X
Power
X
Package
X
Process/
Temperature
Range
Blank
I
B
7200
7201
7202
7280
7281
7282
12
15
20
25
30
35
50
80
Commercial (0
o
C to +70
o
C)
Industrial (-40
o
C to +85
o
C)
Military (-55
o
C to +125
o
C)
Compliant to MIL-STD-883, Class B
256 x 9-Bit FIFO
512 x 9-Bit FIFO
1,024 x 9-Bit FIFO
256 x 9-Bit DUAL FIFO
512 x 9-Bit DUAL FIFO
1,024 x 9-Bit DUAL FIFO
Commercial Only
Commercial and Industrial
Commercial and Military
Commercial and Industrial
Military Only
Commercial Only
Commercial and (Military only for 7201)
Military only for 7201
LA Low Power
P
TP
D
TD
J
SO
L
Plastic DIP
Plastic Thin DIP
CERDIP
Thin CERDIP
Plastic Leaded Chip Carrier
SOIC
Leadless Chip Carrier
Access Time (tA)
Speed in Nanoseconds
2679 drw 21
(1)
P28-1
P28-2
D28-1
D28-3
J32-1
SO28-3
L32-1
PLCC
LCC
(7201 & 7202 Only)
(7201 & 7202 Only)
(7201 & 7202 Only)
(2)
See 7280/7281/7282
data sheet for details
X
G(3) Green
(4)
NOTES:
1. Industrial temperature range product is available for the 15ns and 25ns as a standard product.
2. "A" to be included for IDT7201 and IDT7202 ordering part number.
3. Green parts are available. For specific speeds and packages contact your local sales office.
4. For "P", Plastic Dip, when ordering green package, the suffix is "PDG".
DATASHEET DOCUMENT HISTORY
05/02/2001 pgs. 1, 2, 3, 4, 5 and 14.
04/03/2006 pgs. 1 and 14.
10/22/2008 pg. 1.
