fax id: 5410
1CY 7C42 25
CY7C4425/4205/4215
CY7C4225/4235/4245
64, 256, 512, 1K, 2K, 4K x 18 Synchronous FIFOs
Features
• High-speed, low-power, first-in first-out (FIFO)
memories
• 64 x 18 (CY7C4425)
• 256 x 18 (CY7C4205)
• 512 x 18 (CY7C4215)
• 1K x 18 (CY7C4225)
• 2K x 18 (CY7C4235)
• 4K x 18 (CY7C4245)
• High-speed 100-MHz operation (10 ns read/write cycle
time)
• Low power (ICC =45 mA)
• Fully asynchronous and simultaneous read and write
operation
• Empty, Full, Half Full, and Programmable Almost
Empty/Almost Full status flags
• TTL-compatible
• Retransmit function
• Output Enable (OE) pin
• Independent read and write enable pins
• Center power and ground for reduced noise
• Supports free-running 50% duty cycle clock inputs
• Width Expansion Capability
• Depth Expansion Capability
• Space saving 64-pin 10x10 TQFP, and 14x14 TQFP
• 68-pin PLCC
Functional Description
The CY7C42X5 are high-speed, low-power, first-in first-out
(FIFO) memories with clocked read and write interfaces. All
are 18 bits wide and are pin/functionally compatible to
IDT722x5. The CY7C42X5 can be cascaded to increase FIFO
depth. Programmable features include Almost Full/Almost
Empty flags. These FIFOs provide solutions for a wide variety
of data buffering needs, including high-speed data acquisition,
multiprocessor interfaces, and communications buffering.
These FIFOs have 18-bit input and output ports that are controlled by separate clock and enable signals. The input port is
Cypress Semiconductor Corporation
•
controlled by a free-running clock (WCLK) and a write enable
pin (WEN).
When WEN is asserted, data is written into the FIFO on the
rising edge of the WCLK signal. While WEN is held active, data
is continually written into the FIFO on each cycle. The output
port is controlled in a similar manner by a free-running read
clock (RCLK) and a read enable pin (REN). In addition, the
CY7C42X5 have an output enable pin (OE). The read and
write clocks may be tied together for single-clock operation or
the two clocks may be run independently for asynchronous
read/write applications. Clock frequencies up to 100 MHz are
achievable.
Retransmit and Synchronous Almost Full/Almost Empty flag
features are available on these devices.
Depth expansion is possible using the cascade input (WXI,
RXI), cascade output (WXO, RXO), and First Load (FL) pins.
The WXO and RXO pins are connected to the WXI and RXI
pins of the next device, and the WXO and RXO pins of the last
device should be connected to the WXI and RXI pins of the
first device. The FL pin of the first device is tied to VSS and the
FL pin of all the remaining devices should be tied to VCC.
The CY7C42X5 provides five status pins. These pins are decoded to determine one of five states: Empty, Almost Empty,
Half Full, Almost Full, and Full (see Table 2). The Half Full flag
shares the WXO pin. This flag is valid in the standalone and
width-expansion configurations. In the depth expansion, this
pin provides the expansion out (WXO) information that is used
to signal the next FIFO when it will be activated.
The Empty and Full flags are synchronous, i.e., they change
state relative to either the read clock (RCLK) or the write clock
(WCLK). When entering or exiting the Empty states, the flag is
updated exclusively by the RCLK. The flag denoting Full states
is updated exclusively by WCLK. The synchronous flag architecture guarantees that the flags will remain valid from one
clock cycle to the next. As mentioned previously, the Almost
Empty/Almost Full flags become synchronous if the
VCC/SMODE is tied to VSS. All configurations are fabricated
using an advanced 0.65µ N-Well CMOS technology. Input
ESD protection is greater than 2001V, and latch-up is prevented by the use of guard rings.
3901 North First Street
•
San Jose
•
CA 95134 •
408-943-2600
April 1995 - Revised August 18, 1997
CY7C4425/4205/4215
CY7C4225/4235/4245
D0
Logic Block Diagram
– 17
INPUT
REGISTER
WCLK
WEN
FLAG
PROGRAM
REGISTER
WRITE
CONTROL
DUAL PORT
RAM ARRAY
64 x 18
256 x 18
512 x 18
1K x 18
2K x 18
4K x 18
WRITE
POINTER
RS
FF
EF
FLAG
LOGIC
PAE
PAF
SMODE
READ
POINTER
RESET
LOGIC
FL/RT
WXI
WXO/HF
RXI
RXO
THREE–STATE
OUTPUT REGISTER
EXPANSION
LOGIC
READ
CONTROL
OE
42X5–1
Q0
– 17
RCLK
REN
Pin Configurations
21
22
23
24
25
26
REN
LD
OE
RS
VCC
GND
EF
Q17
Q16
GND
Q15
VCC/SMODE
D16
D17
GND
RCLK
GND
Q15
Q16
VCC
Q17
EF
GND
2 1 68 67 66 65 64 63 62 61
60
59
58
57
56
55
54
53
52
51
50
49
48
VCC/SMODE
Q14
Q13
47
46
45
44
Q6
Q5
GND
Q12
Q11
VCC
Q10
Q9
GND
Q8
Q7
VCC
GND
Q4
D15
D14
D13
D12
D 11
D 10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
3
VCC
RCLK
REN
LD
OE
RS
4
CY7C4425
CY7C4205
CY7C4215
CY7C4225
CY7C4235
CY7C4245
CY7C4425
CY7C4205
CY7C4215
CY7C4225
CY7C4235
CY7C4245
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
Q14
Q13
GND
Q12
Q11
VCC
Q10
Q9
GND
Q8
Q7
Q6
Q5
GND
Q4
VCC
2
Q3
Q0
Q1
GND
Q2
PAE
42x5–2
FL/RT
WCLK
WEN
WXI
VCC
PAF
RXI
FF
WXO/HF
RXO
VCC
Q2
Q3
GND
Q0
Q1
WXO/HF
RXO
RXI
FF
PAF
VCC
WEN
WXI
WCLK
2728 2930 3132 33 34 35 36 37 38 3940 4142 43
PAE
FL/RT
D3
D2
D1
D0
6 5
10
11
12
13
14
15
16
17
18
19
20
TQFP
Top View
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
9 8 7
D14
D13
D12
D11
D10
D9
VCC
D8
GND
D7
D6
D5
D4
GND
D17
D16
D15
PLCC
Top View
42X5–3
CY7C4425/4205/4215
CY7C4225/4235/4245
Selection Guide
7C42X5-10
7C42X5-15
7C42X5-25
7C42X5-35
100
66.7
40
28.6
Maximum Access Time (ns)
8
10
15
20
Minimum Cycle Time (ns)
10
15
25
35
Maximum Frequency (MHz)
Minimum Data or Enable Set-Up (ns)
Minimum Data or Enable Hold (ns)
Maximum Flag Delay (ns)
Operating Current (ICC2)
(mA) @ freq=20MHz
Packages
4
6
7
1
1
2
8
10
15
20
Commercial
45
45
45
45
Industrial
50
50
50
50
CY7C4425
Density
3
0.5
CY7C4205
CY7C4215
CY7C4225
CY7C4235
CY7C4245
64 x 18
256 x 18
512 x 18
1K x 18
2K x 18
4K x 18
68-pin PLCC
64-pin TQFP
(10x10/14x14)
68-pin PLCC
64-pin TQFP
(10x10/14x14)
68-pin PLCC
64-pin TQFP
(10x10/14x14)
68-pin PLCC
64-pin TQFP
(10x10/14x14)
68-pin PLCC
64-pin TQFP
(10x10/14x14)
68-pin PLCC
64-pin TQFP
(10x10/14x14)
Pin Definitions
Signal Name
Description
I/O
Function
D0–17
Data Inputs
I
Data inputs for an 18-bit bus
Q 0–17
Data Outputs
O
Data outputs for an 18-bit bus
WEN
Write Enable
I
Enables the WCLK input
REN
Read Enable
I
Enables the RCLK input
WCLK
Write Clock
I
The rising edge clocks data into the FIFO when WEN is LOW and the FIFO is not
Full. When LD is asserted, WCLK writes data into the programmable flag-offset
register.
RCLK
Read Clock
I
The rising edge clocks data out of the FIFO when REN is LOW and the FIFO is not
Empty. When LD is asserted, RCLK reads data out of the programmable flag-offset register.
WXO/HF
Write Expansion
Out/Half Full Flag
O
Dual-Mode Pin:
Single device or width expansion - Half Full status flag.
Cascaded - Write Expansion Out signal, connected to WXI of next device.
EF
Empty Flag
O
When EF is LOW, the FIFO is empty. EF is synchronized to RCLK.
FF
Full Flag
O
When FF is LOW, the FIFO is full. FF is synchronized to WCLK.
PAE
Programmable
Almost Empty
O
When PAE is LOW, the FIFO is almost empty based on the almost-empty offset
value programmed into the FIFO. PAE is asynchronous when V CC/SMODE is tied
to V CC; it is synchronized to RCLK when V CC/SMODE is tied to V SS.
PAF
Programmable
Almost Full
O
When PAF is LOW, the FIFO is almost full based on the almost full offset value
programmed into the FIFO. PAF is asynchronous when V CC/SMODE is tied to
V CC; it is synchronized to WCLK when V CC/SMODE is tied to VSS.
LD
Load
I
When LD is LOW, D 0 - 17 (O 0 - 17) are written (read) into (from) the programmable-flag-offset register.
FL/RT
First Load/
Retransmit
I
Dual-Mode Pin:
Cascaded - The first device in the daisy chain will have FL tied to V SS; all other
devices will have FL tied to V CC. In standard mode of width expansion, FL is tied
to V SS on all devices.
Not Cascaded - Tied to VSS. Retransmit function is also available in standalone
mode by strobing RT.
WXI
Write Expansion
Input
I
Cascaded - Connected to WXO of previous device.
Not Cascaded - Tied to VSS.
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CY7C4425/4205/4215
CY7C4225/4235/4245
Pin Definitions (continued)
Signal Name
Description
I/O
Function
RXI
Read Expansion
Input
I
Cascaded - Connected to RXO of previous device.
Not Cascaded - Tied to VSS.
RXO
Read Expansion
Output
O
Cascaded - Connected to RXI of next device.
RS
Reset
I
Resets device to empty condition. A reset is required before an initial read or write
operation after power-up.
OE
Output Enable
I
When OE is LOW, the FIFO’s data outputs drive the bus to which they are connected. If OE is HIGH, the FIFO’s outputs are in High Z (high-impedance) state.
VCC/SMODE
Synchronous
Almost Empty/
Almost Full Flags
I
Dual-Mode Pin
Asynchronous Almost Empty/Almost Full flags - tied to VCC.
Synchronous Almost Empty/Almost Full flags - tied to V SS.
(Almost Empty synchronized to RCLK, Almost Full synchronized to WCLK.)
Maximum Ratings
Output Current into Outputs (LOW)............................. 20 mA
Static Discharge Voltage ........................................... >2001V
(per MIL-STD-883, Method 3015)
(Above which the useful life may be impaired. For user guidelines, not tested.)
Storage Temperature ....................................−65°C to +150° C
Latch-Up Current ..................................................... >200 mA
Operating Range
Ambient Temperature with
Power Applied.................................................−55°C to +125° C
Supply Voltage to Ground Potential .................−0.5V to +7.0V
Range
Ambient
Temperature
VCC
DC Voltage Applied to Outputs
in High Z State .....................................................−0.5V to +7.0V
Commercial
0° C to +70° C
5V ± 10%
Industrial[1]
−40° C to +85 ° C
5V ± 10%
DC Input Voltage .................................................−3.0V to +7.0V
Electrical Characteristics Over the Operating Range[2]
Parameter
Description
Test Conditions
VOH
Output HIGH Voltage
VCC = Min.,
IOH = −2.0 mA
VOL
Output LOW Voltage
VCC = Min.,
IOL = 8.0 mA
VIH [3]
Input HIGH Voltage
[3]
Input LOW Voltage
7C42X5-10
7C42X5-15
7C42X5-25
7C42X5-35
Min.
Min.
Min.
Min.
Max.
2.4
0.4
2.2
Max.
2.4
0.4
VCC
2.2
Max.
2.4
0.4
VCC
2.2
Max.
2.4
VCC
2.2
Unit
V
0.4
V
VCC
V
−3.0
0.8
−3.0
0.8
−3.0
0.8
−3.0
0.8
V
IIX
Input Leakage
Current
VCC = Max.
−10
+10
−10
+10
−10
+10
−10
+10
µA
IOS[4]
Output Short
Circuit Current
VCC = Max.,
V OUT = GND
−90
IOZL
I OZH
Output OFF,
High Z Current
OE > VIH,
VSS < VO < VCC
−10
ICC2[5]
Operating Current
VCC = Max.,
IOUT = 0 mA
Com’l
45
45
Ind
50
VCC = Max.,
IOUT = 0 mA
Com’l
Ind
VIL
[6]
ISB
Standby Current
−90
45
45
mA
50
50
50
mA
10
10
10
10
mA
15
15
15
15
mA
+10
−10
mA
µA
+10
−10
−90
+10
+10
−10
−90
Notes:
1. TA is the “instant on” case temperature.
2. See the last page of this specification for Group A subgroup testing information.
3. The V IH and VIL specifications apply for all inputs except WXI, RXI. The WXI, RXI pin is not a TTL input. It is connected to either RXO, WXO of the
previous device or V SS.
4. Test no more than one output at a time for not more than one second.
5. Input signals switch from 0V to 3V with a rise/fall time less than 3 ns, clocks and clock enables switch at 20 MHz, while the data inputs switch at 10 MHz.
Outputs are unloaded.
6. All input signals are connected to VCC . All outputs are unloaded.
4
CY7C4425/4205/4215
CY7C4225/4235/4245
Capacitance[7]
Parameter
Description
CIN
Input Capacitance
COUT
Output Capacitance
Test Conditions
TA = 25 °C, f = 1 MHz,
VCC = 5.0V
Max.
Unit
5
pF
7
pF
AC Test Loads and Waveforms[8, 9]
R11.1K Ω
ALL INPUT PULSES
5V
OUTPUT
3.0V
R2
680Ω
CL
INCLUDING
JIG AND
SCOPE
Equivalent to:
THÉ
EVENIN
90%
10%
90%
10%
GND
< 3 ns
< 3 ns
42X5–4
42X5–5
EQUIVALENT
410Ω
OUTPUT
1.91V
Notes:
7. Tested initially and after any design or process changes that may affect these parameters.
8. CL = 30 pF for all AC parameters except for tOHZ.
9. CL = 5 pF for t OHZ .
Switching Characteristics Over the Operating Range
Parameter
Description
7C42X5-10
7C42X5-15
7C42X5-25
7C42X5-35
Min.
Min.
Min.
Min.
Max.
100
Max.
tA
Data Access Time
tCLK
Clock Cycle Time
10
15
25
35
ns
tCLKH
Clock HIGH Time
4.5
6
10
14
ns
tCLKL
Clock LOW Time
4.5
6
10
14
ns
tDS
Data Set-Up Time
3
4
6
7
ns
tDH
Data Hold Time
0.5
1
1
2
ns
tENS
Enable Set-Up Time
tENH
Enable Hold Time
8
2
10
40
Max. Unit
Clock Cycle Frequency
2
66.7
Max.
tS
2
15
2
28.6
MHz
20
ns
3
4
6
7
ns
0.5
1
1
2
ns
tRS
Reset Pulse
Width[10]
10
15
25
35
ns
tRSR
Reset Recovery Time
8
tRSF
Reset to Flag and Output Time
tPRT
Retransmit Pulse Width
12
15
25
35
ns
tRTR
Retransmit Recovery Time
12
15
25
35
ns
0
0
0
0
ns
10
10
Z[11]
15
15
20
25
ns
35
ns
tOLZ
Output Enable to Output in Low
tOE
Output Enable to Output Valid
3
7
3
8
3
12
3
15
ns
tOHZ
Output Enable to Output in High Z[12]
3
7
3
8
3
12
3
15
ns
tWFF
Write Clock to Full Flag
tREF
tPAFasynch
8
10
15
20
ns
Read Clock to Empty Flag
8
10
15
20
ns
Clock to Programmable Almost-Full Flag[12]
(Asynchronous mode, VCC/SMODE tied to VCC)
12
16
20
25
ns
5
CY7C4425/4205/4215
CY7C4225/4235/4245
Switching Characteristics Over the Operating Range (continued)
Parameter
Description
7C42X5-10
7C42X5-15
7C42X5-25
7C42X5-35
Min.
Min.
Min.
Min.
Max.
Max.
Max.
Max. Unit
tPAFsynch
Clock to Programmable Almost-Full Flag
(Synchronous mode, VCC/SMODE tied to VSS)
8
10
15
20
ns
tPAEasynch
Clock to Programmable Almost-Empty Flag[12]
(Asynchronous mode, VCC/SMODE tied to VCC)
12
16
20
25
ns
tPAEsynch
Clock to Programmable Almost-Full Flag
(Synchronous mode, VCC/SMODE tied to VSS)
8
10
15
20
ns
tHF
Clock to Half-Full Flag
12
16
20
25
ns
tXO
Clock to Expansion Out
20
ns
tXI
Expansion in Pulse Width
3
6.5
10
14
ns
tXIS
Expansion in Set-Up Time
4.5
5
10
15
ns
tSKEW1
Skew Time between Read Clock and Write
Clock for Full Flag
5
6
10
12
ns
tSKEW2
Skew Time between Read Clock and Write
Clock for Empty Flag
5
6
10
12
ns
tSKEW3
Skew Time between Read Clock and Write
Clock for Programmable Almost Empty and Programmable Almost Full Flags.
10
15
18
20
ns
7
10
15
Switching Waveforms
Write Cycle Timing
tCLK
tCLKH
tCLKL
WCLK
tDS
tDH
D0 –D17
tENS
tENH
WEN
NO OPERATION
tWFF
tWFF
FF
tSKEW1[13]
RCLK
REN
42X5–6
Notes:
10. Pulse widths less than minimum values are not allowed.
11. Values guaranteed by design, not currently tested.
12. PAFasynch, tPAEasynch, after program register write will not be valid until 5 ns + tPAF(E).
13. tSKEW1 is the minimum time between a rising RCLK edge and a rising WCLK edge to guarantee that FF will go HIGH during the current 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.
6
CY7C4425/4205/4215
CY7C4225/4235/4245
Switching Waveforms (continued)
Read Cycle Timing
tCLK
tCLKH
tCLKL
RCLK
tENS
tENH
REN
NO OPERATION
tREF
tREF
EF
tA
VALID DATA
Q0 –Q17
tOLZ
tOHZ
tOE
OE
tSKEW2[14]
WCLK
WEN
42X5–7
Reset Timing[15]
tRS
RS
tRSR
REN, WEN,
LD
tRSF
EF,PAE
tRSF
FF,PAF,
HF
tRSF
OE=1[16]
Q0 - Q17
OE=0
42X5–8
Notes:
14. .tSKEW2 is the minimum time between a rising WCLK edge and a rising RCLK edge to guarantee that EF will go HIGH during the current clock cycle. It the time between the
rising edge of WCLK and the rising edge of RCLK is less than tSKEW2, then EF may not change state until the next RCLK edge.
15. The clocks (RCLK, WCLK) can be free-running during reset.
16. After reset, the outputs will be LOW if OE = 0 and three-state if OE = 1.
7
CY7C4425/4205/4215
CY7C4225/4235/4245
Switching Waveforms (continued)
First Data Word Latency after Reset with Simultaneous Read and Write
WCLK
tDS
D0 –D17
D0 (FIRSTVALID WRITE)
D1
D2
D3
D4
tENS
[17]
tFRL
WEN
tSKEW2
RCLK
tREF
EF
REN
tA
tA
Q0 –Q17
[18]
D0
D1
tOLZ
tOE
OE
42X5–9
Empty Flag Timing
WCLK
tDS
tDS
D0
D0 –D17
tENS
D1
tENH
tENS
tENH
WEN
tFRL[17]
tFRL[17]
RCLK
tSKEW2
tREF
tREF
tREF
tSKEW2
EF
REN
OE
tA
D0
Q0 –Q17
42X5–10
Notes:
17. When tSKEW2 > minimum specification, tFRL (maximum) = tCLK + tSKEW2. When tSKEW2 < minimum specification, tFRL (maximum) = either 2*tCLK + tSKEW2 or tCLK + tSKEW2.
The Latency Timing applies only at the Empty Boundary (EF = LOW).
18. The first word is available the cycle after EF goes HIGH, always.
8
CY7C4425/4205/4215
CY7C4225/4235/4245
Switching Waveforms (continued)
Full Flag Timing
NO WRITE
NO WRITE
WCLK
tSKEW1 [13]
tDS
tSKEW1
[13]
DATA WRITE
DATA WRITE
D0 –D17
tWFF
tWFF
tWFF
FF
WEN
RCLK
tENH
tENH
tENS
tENS
REN
OE
LOW
tA
Q0 –Q17
tA
DATAREAD
DATA IN OUTPUT REGISTER
NEXT DATA READ
42X5–11
Half-Full Flag Timing
tCLKL
tCLKH
WCLK
tENS tENH
WEN
tHF
HF
HALF FULL+1
OR MORE
HALF FULL OR LESS
HALF FULL OR LESS
tHF
RCLK
tENS
REN
42X5–12
9
CY7C4425/4205/4215
CY7C4225/4235/4245
Switching Waveforms (continued)
Programmable Almost Empty Flag Timing
tCLKL
tCLKH
WCLK
tENS tENH
WEN
tPAE
PAE]
[19]
n+1 WORDS
IN FIFO
tPAE
n WORDS IN FIFO
RCLK
tENS
REN
42X5–13
Programmable Almost Empty Flag Timing (applies only in SMODE (SMODE is LOW)
tCLKL
tCLKH
WCLK
tENS tENH
WEN
WEN2
tENS tENH
PAE
Note
20
N + 1 WORDS
INFIFO
tSKEW3 [21]
tPAEsynch
Note
22
tPAEsynch
RCLK
tENS
tENS tENH
REN
42X5–14
Notes:
19. PAE offset – n. Number of data words into FIFO already = n.
20. PAE offset – n.
21. tSKEW3 is the minimum time between a rising WCLK and a rising RCLK edge for PAE to change state during that clock cycle. If the time between the edge of WCLK and the
rising RCLK is less than tSKEW3, then PAE may not change state until the next RCLK.
22. If a read is performed on this rising edge of the read clock, there will be Empty + (n – 1) words in the FIFO when PAE goes LOW.
10
CY7C4425/4205/4215
CY7C4225/4235/4245
Switching Waveforms (continued)
Programmable Almost Full Flag Timing
tCLKL
tCLKH
Note 23
WCLK
tENS tENH
WEN
tPAF
PAF
FULL − M WORDS
IN FIFO [25]
[24]
FULL − M + 1 WORDS
IN FIFO [26]
tPAF
RCLK
tENS
REN
42X5–15
Programmable Almost Full Flag Timing (applies only in SMODE (SMODE in LOW))
tCLKH
tCLKL
Note
27
WCLK
tENS tENH
WEN
Note
28
WEN2
tPAF
tENS tENH
PAF
FULL − M WORDS
[29]
IN FIFO
FULL- M+1Ω ORDS
INFIFO
tSKEW3[30]
tPAFsynch
RCLK
tENS
tENS tENH
REN
42X5–16
Notes:
23. PAF offset = m. Number of data words written into FIFO already = 64 – m + 1 for the CY7C4425, 256 – m + 1 for the CY7C4205, 512 – m + 1 for the
CY7C4215. 1024 – m + 1 for the CY7C4225, 2048 – m + 1 for the CY7C4235, and 4096 – m + 1 for the CY7C4245.
24. PAF is offset = m.
25. 64 – m words in CY7C4425, 256 – m words inCY7C4205, 512 – m word in CY7C4215. 1024 – m words in CY7C4225, 2048 – m words in CY7C4235, and
4096 – m words in CY7C4245.
26. 64 – m + 1 words in CY7C4425, 256 – m + 1 words in CY7C4205, 512 – m +1 words in CY7C4215, 1024 – m + 1 CY7C4225, 2048 – m + 1 in CY74235,
and 4096 – m + 1 words in CY7C4245.
27. If a write is performed on this rising edge of the write clock, there will be Full – (m – 1) words of the FIFO when PAF goes LOW.
28. PAF offset = m.
29. 64 – m words in CY7C4425, 256 – m words in FIFO for CY7C4205, 512 – m word in CY7C4215. 1024 – m words in CY7C4225, 2048 – m words in CY7C4235,
and 4096 – m words in CY7C4245.
30. tSKEW3 is the minimum time between a rising RCLK and a rising WCLK edge for PAF to change state during that clock cycle. If the time between the edge of RCLK and the
rising edge of WCLK is less than tSKEW3, then PAF may not change state until the next WCLK rising edge.
11
CY7C4425/4205/4215
CY7C4225/4235/4245
Switching Waveforms (continued)
Write Programmable Registers
tCLK
tCLKL
tCLKH
WCLK
tENS
tENH
LD
tENS
WEN
tDS
tDH
PAE OFFSET
D0 –D17
PAE OFFSET
PAF OFFSET
D0 –D11
42X5–17
Read Programmable Registers
tCLK
tCLKL
tCLKH
RCLK
tENS
tENH
LD
tENS
WEN
tA
UNKNOWN
Q0 –Q17
PAE OFFSET
PAF OFFSET
PAE OFFSET
42X5–18
Write Expansion Out Timing
tCLKH
WCLK
Note 31
tXO
WXO
tENS
tXO
WEN
42X5–19
Note:
31. Write to Last Physical Location.
12
CY7C4425/4205/4215
CY7C4225/4235/4245
Switching Waveforms (continued)
Read Expansion Out Timing
tCLKH
WCLK
Note 32
tXO
RXO
tXO
tENS
REN
42X5–20
Write Expansion In Timing
tXI
WXI
WCLK
tXIS
42X5–21
Read Expansion In Timing
tXI
RXI
tXIS
RCLK
42X5–22
Retransmit Timing[33, 34, 35]
FL/RT
tPRT
tRTR
REN/WEN
EF/FF
and all
async flags
HF/PAE/PAF
42X5–23
Notes:
32. Read from Last Physical Location.
33. Clocks are free running in this case.
34. The flags may change state during Retransmit as a result of the offset of the read and write pointers, but flags will be valid at tRTR.
35. For the synchronous PAE and PAF flags (SMODE), an appropriate clock cycle is necessary after tRTR to update these flags.
13
CY7C4425/4205/4215
CY7C4225/4235/4245
Architecture
Table 1. Write Offset Register
The CY7C42X5 consists of an array of 64 to 4K words of 18
bits each (implemented by a dual-port array of SRAM cells), a
read pointer, a write pointer, control signals (RCLK, WCLK,
REN, WEN, RS), and flags (EF, PAE, HF, PAF, FF). The
CY7C42X5 also includes the control signals WXI, RXI, WXO,
RXO for depth expansion.
WCLK[36]
LD
WEN
0
0
Writing to offset registers:
Empty Offset
Full Offset
0
1
No Operation
1
0
Write Into FIFO
1
1
No Operation
Selection
Resetting the FIFO
Upon power-up, the FIFO must be reset with a Reset (RS)
cycle. This causes the FIFO to enter the Empty condition signified by EF being LOW. All data outputs go LOW after the
falling edge of RS only if OE is asserted. In order for the FIFO
to reset to its default state, a falling edge must occur on RS
and the user must not read or write while RS is LOW.
Note:
36. The same selection sequence applies to reading from the registers. REN
is enabled and read is performed on the LOW-to-HIGH transition of RCLK.
FIFO Operation
Flag Operation
When the WEN signal is active (LOW), data present on the
D0–17 pins is written into the FIFO on each rising edge of the
WCLK signal. Similarly, when the REN signal is active LOW,
data in the FIFO memory will be presented on the Q0–17 outputs. New data will be presented on each rising edge of RCLK
while REN is active LOW and OE is LOW. REN must set up
tENS before RCLK for it to be a valid read function. WEN must
occur tENS before WCLK for it to be a valid write function.
The CY7C42X5 devices provide five flag pins to indicate the
condition of the FIFO contents. Empty and Full are synchronous. PAE and PAF are synchronous if VCC/SMODE is tied to
VSS.
Full Flag
The Full Flag (FF) will go LOW when device is Full. Write operations are inhibited whenever FF is LOW regardless of the
state of WEN. FF is synchronized to WCLK, i.e., it is exclusively updated by each rising edge of WCLK.
An output enable (OE) pin is provided to three-state the Q0–17
outputs when OE is deasserted. When OE is enabled (LOW),
data in the output register will be available to the Q0–17 outputs
after tOE. If devices are cascaded, the OE function will only
output data on the FIFO that is read enabled.
Empty Flag
The FIFO contains overflow circuitry to disallow additional
writes when the FIFO is full, and underflow circuitry to disallow
additional reads when the FIFO is empty. An empty FIFO
maintains the data of the last valid read on its Q0–17 outputs
even after additional reads occur.
The Empty Flag (EF) will go LOW when the device is empty.
Read operations are inhibited whenever EF is LOW, regardless of the state of REN. EF is synchronized to RCLK, i.e., it is
exclusively updated by each rising edge of RCLK.
Programming
The CY7C42X5 features programmable Almost Empty and Almost Full Flags. Each flag can be programmed (described in
the Programming section) a specific distance from the corresponding boundary flags (Empty or Full). When the FIFO contains the number of words or fewer for which the flags have
been programmed, the PAF or PAE will be asserted, signifying
that the FIFO is either Almost Full or Almost Empty. See Table
2 for a description of programmable flags.
Programmable Almost Empty/Almost Full Flag
The CY7C42X5 devices contain two 12-bit offset registers.
Data present on D0–11 during a program write will determine
the distance from Empty (Full) that the Almost Empty (Almost
Full) flags become active. If the user elects not to program the
FIFO’s flags, the default offset values are used (see Table 2).
When the Load LD pin is set LOW and WEN is set LOW, data
on the inputs D0–11 is written into the Empty offset register on
the first LOW-to-HIGH transition of the write clock (WCLK).
When the LD pin and WEN are held LOW then data is written
into the Full offset register on the second LOW-to-HIGH transition of the write clock (WCLK). The third transition of the write
clock (WCLK) again writes to the Empty offset register (see
Table 1). Writing all offset registers does not have to occur at
one time. One or two offset registers can be written and then,
by bringing the LD pin HIGH, the FIFO is returned to normal
read/write operation. When the LD pin is set LOW, and WEN
is LOW, the next offset register in sequence is written.
When the SMODE pin is tied LOW, the PAF flag signal transition is caused by the rising edge of the write clock and the PAE
flag transition is caused by the rising edge of the read clock.
Retransmit
The retransmit feature is beneficial when transferring packets
of data. It enables the receipt of data to be acknowledged by
the receiver and retransmitted if necessary.
The Retransmit (RT) input is active in the standalone and width
expansion modes. The retransmit feature is intended for use
when a number of writes equal to or less than the depth of the
FIFO have occurred since the last RS cycle. A HIGH pulse on
RT resets the internal read pointer to the first physical location
of the FIFO. WCLK and RCLK may be free running but must
be disabled during and tRTR after the retransmit pulse. With
The contents of the offset registers can be read on the output
lines when the LD pin is set LOW and REN is set LOW; then,
data can be read on the LOW-to-HIGH transition of the read
clock (RCLK).
14
CY7C4425/4205/4215
CY7C4225/4235/4245
every valid read cycle after retransmit, previously accessed
data is read and the read pointer is incremented until it is equal
to the write pointer. Flags are governed by the relative locations of the read and write pointers and are updated during a
retransmit cycle. Data written to the FIFO after activation of RT
are transmitted also.
The full depth of the FIFO can be repeatedly retransmitted.
Table 2. Flag Truth Table.
Number of Words in FIFO
7C4425 - 64 x 18
0
7C4205 - 256 x 18
7C4215 - 512 x 18
0
[37
0
[37]
[37]
FF
PAF
HF
PAE
EF
H
H
H
L
L
1 to n
1 to n
1 to n
H
H
H
L
H
(n+1) to 32
(n+1) to 128
(n+1) to 256
H
H
H
H
H
33 to (64 – (m+1))
129 to (256 – (m+1))
257 to (512 – (m+1))
H
H
L
H
H
(64 – m)[38] to 63
(256 – m)[38] to 255
(512 – m)[38] to 511
H
L
L
H
H
64
256
512
L
L
L
H
H
FF
PAF
HF
PAE
EF
Number of Words in FIFO
7C4225 - 1K x 18
7C4235 - 2K x 18
7C4245 - 4K x 18
0
0
0
H
H
H
L
L
1 to n[37]
1 to n[37]
1 to n[37]
H
H
H
L
H
(n+1) to 512
(n+1) to 1024
(n+1) to 2048
H
H
H
H
H
513 to (1024 – (m+1))
1025 to (2048 – (m+1))
2049 to (4096 – (m+1))
H
H
L
H
H
(1024 – m)[38] to 1023
(2048 – m)[38] to 2047
(4096 – m)[38] to 4095
H
L
L
H
H
1024
2048
4096
L
L
L
H
H
Notes:
37. n = Empty Offset (Default Values: CY7C4425 n = 7, CY7C4205 n = 31, CY7C4215 n = 63, CY7C4225/7C4235/7C4245 n = 127).
38. m = Full Offset (Default Values: CY7C4425 n = 7, CY7C4205 n = 31, CY7C4215 n = 63, CY7C4225/7C4235/7C4245 n = 127).
are available. Empty (Full) flags should be created by ANDing
the Empty (Full) flags of every FIFO. This technique will avoid
ready data from the FIFO that is “staggered” by one clock cycle
due to the variations in skew between RCLK and WCLK.
Figure 1 demonstrates a 36-word width by using two CY7C42X5.
Width Expansion Configuration
The CY7C42X5 can be expanded in width to provide word
widths greater than 18 in increments of 18. During width expansion mode all control line inputs are common and all flags
RESET (RS)
DATA IN (D) 36
RESET (RS)
18
18
READ CLOCK (RCLK)
WRITECLOCK (WCLK)
READ ENABLE (REN)
WRITEENABLE (WEN)
OUTPUTENABLE (OE)
LOAD (LD)
PROGRAMMABLE(PAE)
HALF FULL FLAG (HF)
FF
7C4425
7C4205
7C4215
7C4225
7C4235
7C4235
7C4425
7C4205
7C4215
7C4225
7C4235
7C4235
FF
EF
PROGRAMMABLE(PAF)
EMPTYFLAG (EF)
EF
18
FULL FLAG (FF)
DATA OUT (Q)
36
18
FIRST LOAD (FL)
WRITE EXPANSION IN (WXI)
READ EXPANSION IN (RXI)
42X5–24
Figure 1. Block Diagram of 64x36/256 x 36/512 x 36/1024 x 36/2048 x 36/4096 x 36 Synchronous FIFO Memory Used in a
Width Expansion Configuration.
15
CY7C4425/4205/4215
CY7C4225/4235/4245
Depth Expansion Configuration
(with Programmable Flags)
3. The Write Expansion Out (WXO) pin of each device must be
tied to the Write Expansion In (WXI) pin of the next device.
4. The Read Expansion Out (RXO) pin of each device must be
tied to the Read Expansion In (RXI) pin of the next device.
The CY7C42X5 can easily be adapted to applications requiring more than 64/256/512/1024/2048/4096 words of buffering.
Figure 2 shows Depth Expansion using three CY7C42X5s. Maximum depth is limited only by signal loading. Follow these steps:
5. All Load (LD) pins are tied together.
6. The Half-Full Flag (HF) is not available in the Depth Expansion
Configuration.
1. The first device must be designated by grounding the First
Load (FL) control input.
7. EF, FF, PAE, and PAF are created with composite flags by
ORing together these respective flags for monitoring. The
composite PAE and PAF flags are not precise.
2. All other devices must have FL in the HIGH state.
WXO RXO
7C4425
7C4205
7C4215
7C4225
7C4235
7C4235
VCC
FIRSTLOAD (FL)
FF
EF
PAE
PAF
WXI RXI
WXO RXO
7C4425
7C4205
7C4215
7C4225
7C4235
7C4235
DATAIN (D)
VCC
FIRSTLOAD (FL)
DATAOUT (Q)
FF
EF
PAE
PAF
WXI RXI
WRITECLOCK (WCLK)
WXO RXO
WRITE ENABLE (WEN)
READ ENABLE (REN)
7C4425
7C4205
7C4215
7C4225
7C4235
7C4235
RESET(RS)
LOAD (LD)
FF
FF
PAF
READ CLOCK (RCLK)
OUTPUT ENABLE (OE)
EF
EF
PAFWXI RXIPAE
PAE
42X5–23
FIRSTLOAD (FL)
Figure 2. Block Diagram of 192 x 18/768 x 18/1536 x 18/3072 x 18/12288 x 18 Synchronous FIFO Memory
with Programmable Flags used in Depth Expansion Configuration.
16
CY7C4425/4205/4215
CY7C4225/4235/4245
Typical AC and DC Characteristics
NORMALIZED SUPPLY CURRENT
vs. SUPPLY VOLTAGE
1.2
1.2
1.0
VIN =3.0V
TA =25°C
f=100 MHz
0.8
0.6
1.1
1.1
1.0
VIN =3.0V
VCC =5.0V
f=100 MHz
0.9
0.8
4
5
4.5
5.5
−55
6
SUPPLY VOLTAGE (V)
25
1.0
0.9
0.8
5.5
1.0
VCC =5.0V
.75
25
3
4
OUTPUT VOLTAGE (V)
5
OUTPUT SINK CURENT (mA)
35
2
125
75
100
120
140
120
100
80
TA =25°C
VCC =5.0V
60
40
20
0
0
1
2
3
OUTPUT VOLTAGE (V)
17
25
10
−5.0
.50
VCC =5.0V
TA =25°C
275
550
825
CAPACITANCE (pF)
OUTPUT SINK CURRENT vs.
OUTPUT VOLTAGE
TA =25°C
VCC =5.0V
1
25
AMBIENT TEMPERATURE (°C)
55
50
TYPICAL tA CHANGE vs.
OUTPUT LOADING
1.25
OUTPUT SOURCECURRENT
vs. OUTPUT VOLTAGE
0
25
40
0.5
−55
6
SUPPLY VOLTAGE (V)
45
0.7
FREQUENCY (MHz)
NORMALIZED tA
NORMALIZED tA
1.1
5
0.8
0.6
0
125
1.50
TA =25°C
4.5
0.9
NORMALIZED tA vs.
AMBIENT TEMPERATURE
1.2
4
VCC =5.0V
TA =25°C
VIN =3.0V
1.0
AMBIENT TEMPERATURE (°C)
NORMALIZED tA vs.SUPPLY
VOLTAGE
NORMALIZED tA
NORMALIZED ICC
NORMALIZED ICC
NORMALIZED ICC
1.4
OUTPUTS OURCE CURRENT (mA)
NORMALIZED SUPPLY CURRENT
vs. FREQUENCY
NORMALIZED SUPPLY CURRENT
vs. AMBIENT TEMPERATURE
4
1000
CY7C4425/4205/4215
CY7C4225/4235/4245
Ordering Information
64 x 18 Synchronous FIFO
Speed
(ns)
10
15
25
35
Ordering Code
Package
Name
Package
Type
CY7C4425-10AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4425-10ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4425-10JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4425-10AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4425-10ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4425-10JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4425-15AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4425-15ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4425-15JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4425-15AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4425-15ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4425-15JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4425-25AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4425-25ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4425-25JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4425-25AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4425-25ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4425-25JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4425-35AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4425-35ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4425-35JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4425-35AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4425-35ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4425-35JI
J81
68-Lead Plastic Leaded Chip Carrier
18
Operating
Range
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
CY7C4425/4205/4215
CY7C4225/4235/4245
256 x 18 Synchronous FIFO
Speed
(ns)
10
15
25
35
Ordering Code
Package
Name
Package
Type
CY7C4205-10AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4205-10ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4205-10JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4205-10AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4205-10ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4205-10JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4205-15AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4205-15ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4205-15JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4205-15AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4205-15ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4205-15JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4205-25AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4205-25ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4205-25JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4205-25AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4205-25ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4205-25JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4205-35AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4205-35ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4205-35JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4205-35AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4205-35ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4205-35JI
J81
68-Lead Plastic Leaded Chip Carrier
19
Operating
Range
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
CY7C4425/4205/4215
CY7C4225/4235/4245
512 x 18 Synchronous FIFO
Speed
(ns)
10
15
25
35
Ordering Code
Package
Name
Package
Type
CY7C4215-10AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4215-10ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4215-10JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4215-10AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4215-10ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4215-10JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4215-15AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4215-15ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4215-15JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4215-15AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4215-15ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4215-15JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4215-25AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4215-25ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4215-25JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4215-25AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4215-25ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4215-25JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4215-35AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4215-35ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4215-35JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4215-35AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4215-35ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4215-35JI
J81
68-Lead Plastic Leaded Chip Carrier
20
Operating
Range
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
CY7C4425/4205/4215
CY7C4225/4235/4245
1K x 18 Synchronous FIFO
Speed
(ns)
10
15
25
35
Ordering Code
Package
Name
Package
Type
CY7C4225-10AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4225-10ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4225-10JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4225-10AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4225-10ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4225-10JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4225-15AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4225-15ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4225-15JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4225-15AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4225-15ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4225-15JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4225-25AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4225-25ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4225-25JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4225-25AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4225-25ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4225-25JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4225-35AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4225-35ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4225-35JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4225-35AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4225-35ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4225-35JI
J81
68-Lead Plastic Leaded Chip Carrier
21
Operating
Range
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
CY7C4425/4205/4215
CY7C4225/4235/4245
2K x 18 Synchronous FIFO
Speed
(ns)
10
15
25
35
Ordering Code
Package
Name
Package
Type
CY7C4235-10AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4235-10ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4235-10JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4235-10AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4235-10ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4235-10JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4235-15AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4235-15ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4235-15JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4235-15AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4235-15ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4235-15JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4235-25AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4235-25ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4235-25JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4235-25AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4235-25ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4235-25JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4235-35AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4235-35ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4235-35JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4235-35AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4235-35ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4235-35JI
J81
68-Lead Plastic Leaded Chip Carrier
22
Operating
Range
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
CY7C4425/4205/4215
CY7C4225/4235/4245
4K x 18 Synchronous FIFO
Speed
(ns)
10
15
25
35
Ordering Code
Package
Name
Package
Type
CY7C4245-10AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4245-10ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4245-10JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4245-10AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4245-10ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4245-10JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4245-15AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4245-15ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4245-15JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4245-15AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4245-15ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4245-15JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4245-25AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4245-25ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4245-25JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4245-25AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4245-25ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4245-25JI
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4245-35AC
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4245-35ASC
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4245-35JC
J81
68-Lead Plastic Leaded Chip Carrier
CY7C4245-35AI
A65
64-Lead 14x14 Thin Quad Flatpack
CY7C4245-35ASI
A64
64-Lead 10x10 Thin Quad Flatpack
CY7C4245-35JI
J81
68-Lead Plastic Leaded Chip Carrier
23
Operating
Range
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
Commercial
Industrial
CY7C4425/4205/4215
CY7C4225/4235/4245
Package Diagrams
64-Lead Thin Plastic Quad Flat Pack A65
64-Pin Thin Quad Flat Pack A64
24
CY7C4425/4205/4215
CY7C4225/4235/4245
Package Diagrams (continued)
68-Lead Plastic Leaded Chip Carrier J81
© Cypress Semiconductor Corporation, 1997. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use
of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize
its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress
Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.
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