IDT IDT72420L15TPB Cmos syncfifoo 64 x 8, 256 x 8, 512 x 8, 1024 x 8, 2048 x 8 and 4096 x 8 Datasheet

IDT72420
IDT72200
IDT72210
IDT72220
IDT72230
IDT72240
CMOS SyncFIFO
64 x 8, 256 x 8, 512 x 8,
1024 x 8, 2048 x 8 and 4096 x 8
Integrated Device Technology, Inc.
FEATURES:
DESCRIPTION:
•
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•
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•
•
•
•
The IDT72420/72200/72210/72220/72230/72240
SyncFIFO are very high-speed, low-power First-In, FirstOut (FIFO) memories with clocked read and write controls.
The IDT72420/72200/72210/72220/72230/72240 have a 64,
256, 512, 1024, 2048, and 4096 x 8-bit memory array, respectively. These FIFOs are applicable for a wide variety of data
buffering needs, such as graphics, Local Area Networks
(LANs), and interprocessor communication.
These FIFOs have 8-bit input and output ports. The input
port is controlled by a free-running clock (WCLK), and a write
enable pin (WEN). Data is written into the Synchronous FIFO
on every clock when WEN is asserted. The output port is
controlled by another clock pin (RCLK) and a read enable pin
(REN). The read clock can be tied to the write clock for single
clock operation or the two clocks can run asynchronous of one
another for dual clock operation. An output enable pin (OE) is
provided on the read port for three-state control of the output.
These Synchronous FIFOs have two end-point flags, Empty
(EF) and Full (FF). Two partial flags, Almost-Empty (AE) and
Almost-Full (AF), are provided for improved system control.
The partial ( AE) flags are set to Empty+7 and Full-7 for AE and
AF respectively.
The IDT72420/72200/72210/72220/72230/72240 are fabricated using IDT’s high-speed submicron CMOS technology.
Military grade product is manufactured in compliance with the
latest revision of MIL-STD-883, Class B.
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•
•
•
•
64 x 8-bit organization (IDT72420)
256 x 8-bit organization (IDT72200)
512 x 8-bit organization (IDT72210)
1024 x 8-bit organization (IDT72220)
2048 x 8-bit organization (IDT72230)
4096 x 8-bit organization (IDT72240)
12 ns read/write cycle time (IDT72420/72200/72210)
15 ns read/write cycle time (IDT72220/72230/72240)
Read and write clocks can be asynchronous or
coincidental
Dual-Ported zero fall-through time architecture
Empty and Full flags signal FIFO status
Almost-empty and almost-full flags set to Empty+7 and
Full-7, respectively
Output enable puts output data bus in high-impedance
state
Produced with advanced submicron CMOS technology
Available in 28-pin 300 mil plastic DIP and 300 mil
ceramic DIP
For surface mount product please see the IDT72421/
72201/72211/72221/72231/72241 data sheet
Military product compliant to MIL-STD-883, Class B
Industrial temperature range (-40OC to +85OC) is
available, tested to military electrical specifications
FUNCTIONAL BLOCK DIAGRAM
D0 - D7
WCLK
WEN
•
INPUT REGISTER
•
FLAG
LOGIC
WRITE CONTROL
LOGIC
••
RAM ARRAY
64 x 8
256 x 8
512 x 8
••
WRITE POINTER
EF
AE
AF
FF
READ POINTER
READ CONTROL
LOGIC
OUTPUT REGISTER
•
RESET LOGIC
RS
RCLK
OE
Q0 - Q7
REN
2680 drw 01
The IDT logo is a registered trademark and SyncFIFO is a trademark of Integrated Device Technology, Inc.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
1996 Integrated Device Technology, Inc.
NOVEMBER 1996
DSC-2680/6
For latest information contact IDT's web site at www.idt.com or fax-on-demand at 408-492-8391.
5.12
1
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN CONFIGURATION
D4
1
28
D5
D3
2
27
D6
D2
3
26
D7
D1
4
25
D0
5
24
RS
WEN
6
23
WCLK
22
VCC
21
Q7
AF
AE
7
P28-2
C28-1
GND
8
RCLK
9
20
Q6
10
19
Q5
11
18
Q4
12
17
Q3
13
16
Q2
14
15
Q1
REN
OE
EF
FF
Q0
DIP TOP
VIEW
2680 drw 02
PIN DESCRIPTIONS
Symbol
D0 - D7
Name
Data Inputs
RS
Reset
I
WCLK
Write Clock
I
WEN
Write Enable
I
Q0 - Q7
Data Outputs
O
Data outputs for a 8-bit bus.
RCLK
Read Clock
I
Data is read from the FIFO on a LOW-to-HIGH transition of RCLK when REN is asserted.
REN
Read Enable
I
OE
Output Enable
I
EF
Empty Flag
O
Almost-Empty
Flag
O
When AE is LOW, the FIFO is almost empty based on the offset Empty+7. AE is synchronized
to RCLK.
AF
Almost-Full Flag
O
When AF is LOW, the FIFO is almost full based on the offset Full-7.
WCLK.
FF
Full Flag
O
VCC
Power
One +5 volt power supply pin.
GND
Ground
One 0 volt ground pin.
AE
I/O
I
Description
Data inputs for a 8-bit bus.
When RS is set LOW, internal read and write pointers are set to the first location of the RAM
array, FF and AF go HIGH, and AE and EF go LOW. A reset is required before an initial WRITE
after power-up.
Data is written into the FIFO on a LOW-to-HIGH transition of WCLK when WEN is asserted.
When WEN is LOW, data is written into the FIFO on every LOW-to-HIGH transition of WCLK.
Data will not be written into the FIFO if the FF is LOW.
When REN is LOW, data is read from the FIFO on every LOW-to-HIGH transition of RCLK.
Data will not be read from the FIFO if the EF is LOW.
When OE is LOW, the data output bus is active. If OE is HIGH, the output data bus will be in a
high-impedance state.
When EF is LOW, the FIFO is empty and further data reads from the output are inhibited. When
EF is HIGH, the FIFO is not empty. EF is synchronized to RCLK.
AF is synchronized to
When FF is LOW, the FIFO is full and further data writes into the input are inhibited. When FF is
HIGH, the FIFO is not full. FF is synchronized to WCLK.
2680 tbl 01
5.12
2
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
ABSOLUTE MAXIMUM RATINGS(1)
Symbol
VTERM
TA
TBIAS
TSTG
IOUT
Rating
Commercial
Terminal Voltage –0.5 to + 7.0
with Respect to
GND
Operating
0 to + 70
Temperature
Temperature
–55 to + 125
Under Bias
Storage
–55 to + 125
Temperature
DC Output
50
Current
RECOMMENDED OPERATING CONDITIONS
Military
Unit
–0.5 to + 7.0
V
–55 to + 125
°C
–65 to + 135
°C
–65 to + 135
°C
50
mA
Symbol
VCCM
VCCC
GND
VIH
VIH
VIL
Parameter
Min.
Typ.
Max.
Unit
Military Supply Voltage
Commercial Supply
Voltage
Supply Voltage
Input High Voltage
Commercial
Input High Voltage
Military
Input Low Voltage
Commercial & Military
4.5
4.5
5.0
5.0
5.5
5.5
V
V
0
2.0
0
—
0
—
V
V
2.2
—
—
V
—
—
0.8
V
2680 tbl 03
2680 tbl 02
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.
CAPACITANCE (TA = +25°C, f = 1.0 MHz)
Symbol
CIN (2)
Parameter
Input Capacitance
COUT(1, 2) Output Capacitance
Conditions
Max.
Unit
VIN = 0V
10
pF
VOUT = 0V
10
NOTES:
1. With output deselected. (OE = HIGH)
2. Characterized values, not currently tested.
pF
2680 tbl 04
DC ELECTRICAL CHARACTERISTICS
(Commercial: VCC = 5V ± 10%, TA = 0°C to +70°C; Military: VCC = 5V ± 10%, TA = –55°C to +125°C)
Symbol
Parameter
IDT72420
IDT72200
IDT72210
Commercial
tCLK = 12, 15, 20, 25, 35, 50 ns
Min.
Typ.
Max.
IDT72420
IDT72200
IDT72210
Military
tCLK = 20, 25,35, 50 ns
Min.
Typ.
Max.
Units
ILI(1)
Input Leakage Current (any input)
–1
—
1
–10
—
10
µA
ILO(2)
Output Leakage Current
–10
—
10
–10
—
10
µA
VOH
Output Logic “1” Voltage, IOH = –2 mA
2.4
—
—
2.4
—
—
V
VOL
Output Logic “0” Voltage, IOL = 8 mA
—
—
0.4
—
—
0.4
V
ICC1(3)
Active Power Supply Current
—
—
80
—
—
100
mA
2680 tbl 05
Symbol
Parameter
IDT72220
IDT72230
IDT72240
Commercial
tCLK = 15, 20, 25, 35, 50 ns
Min.
Typ.
Max.
IDT72220
IDT72230
IDT72240
Military
tCLK = 25, 35, 50 ns
Min.
Typ.
Max.
Units
ILI(1)
Input Leakage Current (any input)
–1
—
1
–10
—
10
µA
ILO(2)
Output Leakage Current
–10
—
10
–10
—
10
µA
VOH
Output Logic “1” Voltage, IOH = –2 mA
2.4
—
—
2.4
—
—
V
VOL
Output Logic “0” Voltage, IOL = 8 mA
—
—
0.4
—
—
0.4
V
ICC1(4)
Active Power Supply Current
—
—
80
—
—
100
mA
NOTES:
1. Measurements with 0.4 ≤ VIN ≤ VCC.
2. OE ≥ VIH, 0.4 ≤ VOUT ≤ VCC.
3 & 4.
Measurements are made with outputs unloaded. Tested at fCLK = 20 MHZ.
(3) Typical ICC1 = 30 + (fCLK*0.5/MHz) + (fCLK*CL*0.02/MHz-pF) mA
(4) Typical ICC1 = 32 + (fCLK*0.6/MHz) + (fCLK*CL*0.02/MHz-pF) mA
fCLK = 1 / tCLK
CL = external capacitive load (30 pF typical)
5.12
2680 tbl 06
3
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
AC ELECTRICAL CHARACTERISTICS
(Commercial: VCC = 5V ± 10%, TA = 0°C to + 70°C; Military: VCC = 5V ± 10%, TA = –55°C to +125°C)
Commercial
Comm. & Mil.
72200L12 72200L15 72200L20 72200L25
72210L12 72210L15 72210L20 72210L25
72420L12 72420L15 72420L20 72420L25
Symbol
Parameter
Min. Max. Min. Max. Min. Max. Min. Max. Min. Max.
fS
Clock Cycle Frequency
tA
Data Access Time
2
8
2
tCLK
Clock Cycle Time
12
—
15
tCLKH
Clock High Time
5
—
tCLKL
Clock Low Time
5
—
tDS
Data Set-up Time
tDH
Data Hold Time
tENS
Enable Set-up Time
tENH
Enable Hold Time
Width(1)
Comm.
72200L35
72210L35
72420L35
— 83.3
— 66.7
—
50
10
2
—
20
6
—
6
—
— 28.6
Comm/Mil
72200L50
72210L50
72420L50
Min.Max. Unit
—
40
— 20
MHz
12
3
15
3
20
3
25
ns
—
25
—
35
—
50 —
ns
8
—
10
—
14
—
20 —
ns
8
—
10
—
14
—
20 —
ns
3
—
4
—
5
—
6
—
8
—
10 —
ns
0.5
—
1
—
1
—
1
—
2
—
2
—
ns
3
—
4
—
5
—
6
—
8
—
10 —
ns
0.5
—
1
—
1
—
1
—
2
—
2
—
ns
tRS
Reset Pulse
12
—
15
—
20
—
25
—
35
—
50 —
ns
tRSS
Reset Set-up Time
12
—
15
—
20
—
25
—
35
—
50 —
ns
tRSR
Reset Recovery Time
12
—
15
—
20
—
25
—
35
—
50 —
ns
tRSF
Reset to Flag and Output Time
—
12
—
15
—
20
—
25
—
35
— 50
ns
tOLZ
Output Enable to Output in Low-Z(2)
0
—
0
—
0
—
0
—
0
—
0
—
ns
tOE
Output Enable to Output Valid
3
7
3
8
3
10
3
13
3
15
3
28
ns
tOHZ
Output Enable to Output in High-Z(2)
3
7
3
8
3
10
3
13
3
15
3
28
ns
tWFF
Write Clock to Full Flag
—
8
—
10
—
12
—
15
—
20
— 30
ns
tREF
Read Clock to Empty Flag
—
8
—
10
—
12
—
15
—
20
— 30
ns
tAF
Write Clock to Almost-Full Flag
—
8
—
10
—
12
—
15
—
20
— 30
ns
tAE
Read Clock to Almost-Empty Flag
—
8
—
10
—
12
—
15
—
20
— 30
ns
tSKEW1 Skew time between Read Clock &
Write Clock for Empty Flag & Full Flag
5
—
6
—
8
—
10
—
12
—
15 —
ns
tSKEW2 Skew time between Read Clock &
Write Clock for Almost-Empty Flag &
Almost-Full Flag
22
—
28
—
35
—
40
—
42
—
45 —
ns
NOTES:
1. Pulse widths less than minimum values are not allowed.
2. Values guaranteed by design, not currently tested.
2680 tbl 07
5.12
4
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
AC ELECTRICAL CHARACTERISTICS
(Commercial: VCC = 5V ± 10%, TA = 0°C to + 70°C; Military: VCC = 5V ± 10%, TA = –55°C to +125°C)
Symbol Parameter
Commercial
72220L12
72220L15
72230L12
72230L15
72240L12
72240L15
Min. Max. Min. Max.
Commercial & Military
72220L20
72220L25
72230L20
72230L25
72240L20
72240L25
Min. Max. Min. Max.
Comm.
72220L35
72230L35
72240L35
Min. Max.
Comm./Mil.
72220L50
72230L50
72240L50
Min. Max.
Unit
fS
Clock Cycle Frequency
—
83.3
—
66.7
—
50
—
40
—
28.6
—
20
MHz
tA
Data Access Time
2
8
2
10
2
12
3
15
3
20
3
25
ns
tCLK
Clock Cycle Time
12
—
15
—
20
—
25
—
35
—
50
—
ns
tCLKH
Clock High Time
5
—
6
—
8
—
10
—
14
—
20
—
ns
tCLKL
Clock Low Time
5
—
6
—
8
—
10
—
14
—
20
—
ns
tDS
Data Set-up Time
3
—
4
—
5
—
6
—
8
—
10
—
ns
tDH
Data Hold Time
.5
—
1
—
1
—
1
—
2
—
2
—
ns
tENS
Enable Set-up Time
3
—
4
—
5
—
6
—
8
—
10
—
ns
ns
tENH
Enable Hold Time
.5
—
1
—
1
—
1
—
2
—
2
—
tRS
Reset Pulse Width(1)
12
—
15
—
20
—
25
—
35
—
50
—
ns
tRSS
Reset Set-up Time
12
—
15
—
20
—
25
—
35
—
50
—
ns
tRSR
Reset Recovery Time
12
—
15
—
20
—
25
—
35
—
50
—
ns
tRSF
Reset to Flag and Output Time
—
12
—
15
—
20
—
25
—
35
—
50
ns
tOLZ
Output Enable to Output in Low-Z(2)
0
—
0
—
0
—
0
—
0
—
0
—
ns
tOE
Output Enable to Output Valid
3
7
3
8
3
10
3
13
3
15
3
23
ns
tOHZ
Output Enable to Output in High-Z(2)
3
7
3
8
3
10
3
13
3
15
3
23
ns
tWFF
Write Clock to Full Flag
—
8
—
10
—
12
—
15
—
20
—
30
ns
tREF
Read Clock to Empty Flag
—
8
—
10
—
12
—
15
—
20
—
30
ns
tAF
Write Clock to Almost-Full Flag
—
8
—
10
—
12
—
15
—
20
—
30
ns
tAE
Read Clock to Almost-Empty Flag
—
8
—
10
—
12
—
15
—
20
—
30
ns
tSKEW1 Skew time between Read Clock
& Write Clock for Empty Flag &
Full Flag
tSKEW2 Skew time between Read Clock &
Write Clock for Almost-Empty Flag
& Almost-Full Flag
5
—
6
—
8
—
10
—
12
—
15
—
ns
22
—
28
—
35
—
40
—
42
—
45
—
ns
NOTES:
1. Pulse widths less than minimum values are not allowed.
2. Values guaranteed by design, not currently tested.
2680 tbl 08
5V
1.1KΩ
AC TEST CONDITIONS
Input Pulse Levels
Input Rise/Fall Times
3ns
Input Timing Reference Levels
1.5V
Output Reference Levels
1.5V
Output Load
D.U.T.
GND to 3.0V
680Ω
30pF*
See Figure 1
2680 tbl 09
2680 drw 03
or equivalent circuit
Figure 1. Output Load
*Includes jig and scope capacitances.
5.12
5
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
SIGNAL DESCRIPTIONS
INPUTS:
Data In (D0–D7) — Data inputs for 8-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. The Full Flag (FF) and Almost Full Flag (AF) will be reset
to HIGH after tRSF. The Empty Flag (EF) and Almost Empty
Flag (AE) will be reset to LOW after tRSF. During reset, the
output register is initialized to all zeros.
Write Clock (WCLK) — A write cycle is initiated on the LOWto-HIGH transition of the write clock (WCLK). Data set-up and
hold times must be met in respect to the LOW-to-HIGH
transition of the write clock (WCLK). The Full Flag (FF) and
Almost Full Flag (AF) are synchronized with respect to the
LOW-to-HIGH transition of the write clock (WCLK).
The write and read clocks can be asynchronous or coincident.
Write Enable (WEN) — When Write Enable (WEN) is LOW,
data can be loaded into the input register and RAM array on
the LOW-to-HIGH transition of every write clock (WCLK).
Data is stored in the RAM array sequentially and independently of any on-going read operation.
When Write Enable (WEN) is HIGH, the input register holds
the previous data and no new data is allowed to be loaded into
the register.
To prevent data overflow, the Full Flag (FF) will go LOW,
inhibiting further write operations. Upon the completion of a
valid read cycle, the Full Flag (FF) will go HIGH after tWFF,
allowing a valid write to begin. Write Enable (WEN) is ignored
when the FIFO is full.
Read Clock (RCLK) — Data can be read on the outputs on the
LOW-to-HIGH transition of the read clock (RCLK). The Empty
Flag (EF) and Almost-Empty Flag (AE) are synchronized with
respect to the LOW-to-HIGH transition of the read clock
(RCLK).
The write and read clocks can be asynchronous or coincident.
Read Enable (REN) — When Read Enable (REN) is LOW,
data is read from the RAM array to the output register on the
LOW-to-HIGH transition of the read clock (RCLK).
When Read Enable (REN) is HIGH, the output register
holds the previous data and no new data is allowed to be
loaded into the register.
When all the data has been read from the FIFO, the Empty
Flag (EF) will go LOW, inhibiting further read operations. Once
a valid write operation has been accomplished, the Empty
Flag (EF) will go HIGH after tREF and a valid read can begin.
Read Enable (REN) is ignored when the FIFO is empty.
Output Enable (OE) — When Output Enable (OE) is enabled
(LOW), the parallel output buffers receive data from the output
register. When Output Enable (OE) is disabled (HIGH), the
Q output data bus is in a high-impedance state.
OUTPUTS:
Full Flag (FF) — The Full Flag (FF) will go LOW, inhibiting
further write operation, when the device is full. If no reads are
performed after Reset (RS), the Full Flag (FF) will go LOW
after 64 writes for the IDT72420, 256 writes for the IDT72200,
512 writes for the IDT72210, 1024 writes for the IDT72220,
2048 writes for the IDT72230, and 4096 writes for the IDT72240.
The Full Flag (FF) is synchronized with respect to the LOWto-HIGH transition of the write clock (WCLK).
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 the device is empty.
The Empty Flag (EF) is synchronized with respect to the
LOW-to-HIGH transition of the read clock (RCLK).
Almost Full Flag (AF) — The Almost Full Flag (AF) will go
LOW when the FIFO reaches the Almost-Full condition. If no
reads are performed after Reset (RS), the Almost Full Flag
(AF) will go LOW after 57 writes for the IDT72420, 249 writes
for the IDT72200, 505 writes for the IDT72210, 1017 writes for
the IDT72220, 2041 writes for the IDT72230 and 4089 writes
for the IDT72240.
The Almost Full Flag (AF) is synchronized with respect to
the LOW-to-HIGH transition of the write clock (WCLK).
Almost Empty Flag (AE) — The Almost Empty Flag (AE) will
go LOW when the FIFO reaches the Almost-Empty condition.
If no reads are performed after Reset (RS), the Almost Empty
Flag (AE) will go HIGH after 8 writes for the IDT72420,
IDT72200, IDT72210, IDT72220, IDT72230 and IDT72240.
The Almost Empty Flag (AE) is synchronized with respect
to the LOW-to-HIGH transition of the read clock (RCLK).
Data Outputs (Q0–Q7) — Data outputs for a 8-bit wide data.
5.12
6
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
TABLE 1: STATUS FLAGS
Number of Words in FIFO
IDT72420
IDT72200
IDT72210
IDT72220
IDT72230
IDT72240
FF
AF
AE
EF
0
0
0
0
0
0
H
H
L
L
1 to 7
1 to 7
1 to 7
1 to 7
1 to 7
1 to 7
H
H
L
H
8 to 56
8 to 248
8 to 504
8 to 1016
8 to 2040
8 to 4088
H
H
H
H
57 to 63
249 to 255
505 to 511
64
256
512
1017 to 1023 2041 to 2047 4089 to 4095
1024
2048
4096
H
L
H
H
L
L
H
H
2680 tbl 10
tRS
RS
tRSS
tRSR
tRSS
tRSR
REN
WEN
tRSF
EF, AE
tRSF
FF, AF
tRSF
OE = 1
Q0 - Q7
(1)
OE = 0
2680 drw 04
NOTE:
1. After reset, the outputs will be LOW if OE = 0 and tri-state if OE = 1.
2. The clocks (RCLK, WCLK) can be free-running during reset.
Figure 2. Reset Timing
5.12
7
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
tCLK
tCLKH
tCLKL
WCLK
tDS
tDH
D0 - D7
DATAIN VALID
tENS
tENH
WEN
NO OPERATION
tWFF
tWFF
FF
tSKEW1
(1)
RCLK
REN
2680 drw 05
NOTE:
1. tSKEW1 is the minimum time between a rising RCLK edge and a rising WCLK edge for FF to change during the curent clock cycle. If the time between
the rising edge of RCLK and the rising edge of WCLK is less than tSKEW1, then FF may not change state until the next WCLK edge.
Figure 3. Write Cycle Timing
5.12
8
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
tCLK
tCLKH
tCLKL
RCLK
tENS
tENH
REN
NO OPERATION
tREF
tREF
EF
tA
Q0 - Q7
VALID DATA
tOLZ
tOHZ
tOE
OE
tSKEW1(1)
WCLK
WEN
2680 drw 06
NOTE:
1. tSKEW1 is the minimum time between a rising WCLK edge and a rising RCLK edge for EF to change during the curent clock cycle. If the time between
the rising edge of WCLK and the rising edge of RCLK is less than tSKEW1, then EF may not change state until the next RCLK edge.
Figure 4. Read Cycle Timing
5.12
9
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
WCLK
tDS
D0 - D7
D0 (first valid write)
D1
D2
D3
tENS
WEN
tFRL
tSKEW1
(1)
RCLK
EF
tREF
REN
tA
tA
Q0 - Q7
D0
D1
tOLZ
tOE
OE
NOTE:
1. When tSKEW1 ≥ minimum specification, tFRL maximum = tCLK + tSKEW1
When tSKEW1 < minimum specification, tFRL maximum = 2tCLK + tSKEW1 or tCLK + tSKEW1
The Latency Timing apply only at the Empty Boundry (EF = LOW).
2680 drw 07
Figure 5. First Data Word Latency Timing
5.12
10
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
NO WRITE
NO WRITE
WCLK
tDS
tDS
tSKEW1
tSKEW1
D0 - D7
DATA WRITE
DATA WRITE
tWFF
tWFF
tWFF
FF
WEN
RCLK
tENH
tENH
tENS
tENS
REN
OE
Q0 - Q7
LOW
tA
tA
DATA IN OUTPUT REGISTER
DATA READ
NEXT DATA READ
2680 drw 08
Figure 6. Full Flag Timing
5.12
11
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
WCLK
tDS
D0 - D7
tDS
DATA WRITE 1
DATA WRITE 2
tENH
tENS
tENS
tENH
WEN
tFRL (1)
tFRL
(1)
tSKEW1
tSKEW1
RCLK
tREF
tREF
tREF
EF
REN
OE
LOW
tA
Q0 - Q7
DATA READ
DATA IN OUTPUT REGISTER
NOTE:
1. When tSKEW1 ≥ minimum specification, tFRL maximum = tCLK + tSKEW1
When tSKEW1 < minimum specification, tFRL maximum = 2tCLK + tSKEW1 or tCLK + tSKEW1
The Latency Timing apply only at the Empty Boundry (EF = LOW).
2680 drw 09
Figure 7. Empty Flag Timing
5.12
12
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
tCLKL
tCLKH
(2)
WCLK
tENS
tENH
WEN
tAF
AF
Full - 7 words in FIFO
Full - 8 words in FIFO
tSKEW2 (1)
tAF
RCLK
tENS
tENH
REN
2680 drw 10
NOTES:
1. tSKEW2 is the minimum time between a rising RCLK edge and a rising WCLK edge for AF to change during the curent clock cycle. If the time between
the rising edge of RCLK and the rising edge of WCLK is less than tSKEW2, then AF may not change state until the next WCLK edge.
2. If a write is performed on this rising edge of the write clock, there will be Full - 6 words in the FIFO when AF goes LOW.
Figure 8. Almost Full Flag Timing
5.12
13
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
tCLKL
tCLKH
WCLK
tENS
tENH
WEN
Empty+8
AE
Empty+7
(1)
tSKEW2
tAE
tAE
(2)
RCLK
tENS
tENH
REN
2680 drw 11
NOTES:
1. tSKEW2 is the minimum time between a rising WCLK edge and a rising RCLK edge for AE to change during the curent clock cycle. If the time between
the rising edge of WCLK and the rising edge of RCLK is less than tSKEW2, then AE may not change state until the next RCLK edge.
2. If a read is performed on this rising edge of the read clock, there will be Empty - 6 words in the FIFO when AE goes LOW.
Figure 9. Almost Empty Flag Timing
5.12
14
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
OPERATING CONFIGURATIONS
SINGLE DEVICE CONFIGURATION - A single IDT72420/
72200/72210/72220/72230/72240 may be used when the
application requirements are for 64/256/512/1024/2048/4096
words or less. See Figure 10.
RESET (RS)
WRITE CLOCK (WCLK)
READ CLOCK (RCLK)
WRITE ENABLE (WEN)
READ ENABLE (REN)
OUTPUT ENABLE (OE)
IDT
72420/72200/
72210/
72220/
72230/
72240
DATA IN (D0-D7)
FULL FLAG (FF)
DATA OUT (Q0- Q7)
EMPTY FLAG (EF)
ALMOST FULL (AF)
ALMOST EMPTY(AE)
2680 drw 12
Figure 10. Block Diagram of Single 64 x 8/256 x 8/512 x 8/1024 x 8/2048 x 8/4096 x 8 Synchronous FIFO
WIDTH EXPANSION CONFIGURATION - Word width may
be increased simply by connecting the corresponding input
control signals of multiple devices. A composite flag should be
created for each of the end-point status flags (EF and FF) The
partial status flags (AE and AF) can be detected from any one
device. Figure 11 demonstrates a 16-bit word width by using
two IDT72420/72200/72210/72220/72230/72240s. Any word
width can be attained by adding additional IDT72420/72200/
72210/72220/72230/72240s.
RESET (RS)
DATA IN (D)
16
RESET (RS)
8
8
READ CLOCK (RCLK)
WRITE CLOCK (WCLK)
READ ENABLE (REN)
WRITE ENABLE (WEN)
ALMOST FULL (AF)
FULL FLAG (FF) #1
FULL FLAG (FF) #2
OUTPUT ENABLE (OE)
IDT
72420/
72200/
72210/
72220/
72230/
72240
IDT
72420/
72200/
72210/
72220/
72230/
72240
8
ALMOST EMPTY (AE)
EMPTY FLAG (EF) #1
EMPTY FLAG (EF) #2
8
DATA OUT (Q)
16
2680 drw 13
Figure 11. Block Diagram of 64 x 16/256 x 16/512 x 16/1024 x 16/2048 x 16/4096 x 16 Synchronous FIFO
Used in a Width Expansion Configuration
5.12
15
IDT72420/72200/72210/72220/72230/72240 CMOS SyncFIFO
64 X 8, 256 X 8, 512 X 8, 1024 X 8, 2048 X 8 and 4096 X 8
MILITARY AND COMMERCIAL TEMPERATURE RANGES
DEPTH EXPANSION - The IDT72420/72200/72210/72220/
72230/72240 can be adapted to applications when the requirements are for greater than 64/256/512/1024/2048/4096
words. Depth expansion is possible by using expansion logic
to direct the flow of data. A typical application would have the
expansion logic alternate data accesses from one device to
the next in a sequential manner.
Please see the Application Note “DEPTH EXPANSION
IDT'S SYNCHRONOUS FIFOs USING RING COUNTER
APPROACH” for details of this configuration.
ORDERING INFORMATION
IDT
XXXXX
Device
Type
XX
XX
X
Power Speed Package
X
Process /
Temperature
Range
BLANK Commercial (0°C to +70°C)
B
Military (–55°C to +125°C) Compliant to MIL-STD-883, Class B
TP
TC
Plastic THINDIP
Sidebraze THINDIP
12
15
20
25
35
50
Commercial Only
Commercial Only
Commercial and Military
Commercial and Military
Commercial Only
Commercial and Military
L
Low Power
72420
72200
72210
72220
72230
72240
64 x 8 Synchronous FIFO
256 x 8 Synchronous FIFO
512 x 8 Synchronous FIFO
1024 x 8 Synchronous FIFO
2048 x 8 Synchronous FIFO
4098 x 8 Synchronous FIFO
5.12
Clock Cycle Time (tCLK)
Speed in Nanoseconds
2680 drw 14
16
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