CY7C144, CY7C145
8K x 8/9 Dual-Port Static RAM
with SEM, INT, BUSY
Features
Functional Description
■
True Dual-Ported Memory Cells that Enable Simultaneous
Reads of the same Memory Location
■
8K x 8 Organization (CY7C144)
■
8K x 9 Organization (CY7C145)
■
0.65-Micron CMOS for optimum Speed and Power
■
High Speed Access: 15 ns
■
Low Operating Power: ICC = 160 mA (max.)
■
Fully Asynchronous Operation
■
Automatic Power Down
■
TTL Compatible
■
Master/Slave Select Pin enables Bus Width Expansion to 16/18
Bits or more
■
Busy Arbitration Scheme provided
■
Semaphores included to permit Software Handshaking
between Ports
■
INT Flag for Port-to-Port Communication
■
Available in 68-pin PLCC, 64-pin and 80-pin TQFP
■
Pb-free Packages available
Logic Block Diagram
The CY7C144 and CY7C145 are high speed CMOS 8K x 8 and
8K x 9 dual-port static RAMs. Various arbitration schemes are
included on the CY7C144/5 to handle situations when multiple
processors access the same piece of data. Two ports are
provided permitting independent, asynchronous access for
reads and writes to any location in memory. The CY7C144/5 can
be used as a standalone 64/72-Kbit dual-port static RAM or
multiple devices can be combined in order to function as a
16/18-bit or wider master/slave dual-port static RAM. An M/S pin
is provided for implementing 16/18-bit or wider memory applications without the need for separate master and slave devices or
additional discrete logic. Application areas include interprocessor/multiprocessor
designs,
communications
status
buffering, and dual-port video/graphics memory.
Each port has independent control pins: chip enable (CE), read
or write enable (R/W), and output enable (OE). Two flags, BUSY
and INT, are provided on each port. BUSY signals that the port
is trying to access the same location currently being accessed
by the other port. The interrupt flag (INT) permits communication
between ports or systems by means of a mail box. The
semaphores are used to pass a flag, or token, from one port to
the other to indicate that a shared resource is in use. The
semaphore logic is comprised of eight shared latches. Only one
side can control the latch (semaphore) at any time. Control of a
semaphore indicates that a shared resource is in use. An
automatic power down feature is controlled independently on
each port by a chip enable (CE) pin or SEM pin.
R/W L
R/W R
CE L
OE L
CE R
OE R
(7C145) I/O8L
I/O7L
I/O
CONTROL
I/O0L
I/O 8R(7C145)
I/O 7R
I/O
CONTROL
I/O 0R
[1, 2]
BUSYL
BUSY R [1, 2]
A 12L
A 12R
ADDRESS
DECODER
A 0L
CEL
OEL
MEMORY
ARRAY
ADDRESS
DECODER
INTERRUPT
SEMAPHORE
ARBITRATION
R/W L
A 0R
CE R
OE R
R/W R
SEM L
INT L [2]
SEMR
INTR [2]
M/S
Notes
1. BUSY is an output in master mode and an input in slave mode.
2. Interrupt: push-pull output and requires no pull-up resistor.
Cypress Semiconductor Corporation
Document #: 38-06034 Rev. *F
•
198 Champion Court
•
San Jose, CA 95134-1709
•
408-943-2600
Revised March 22, 2010
[+] Feedback
CY7C144, CY7C145
Pin Configuration
A2L
A1L
BUSYL
GND
A6L
A5L
49
54
A7L
A12L
56
55
A8L
VCC
57
51
50
CEL
NC
A9L
SEML
59
52
R/WL
60
53
OEL
A11L
A10L
IO 0L
62
61
58
IO 1L
1
48
A4L
2
47
3
4
46
45
A3L
A2L
5
44
A0L
IO 6L
IO 7L
6
43
7
42
INTL
BUSYL
GND
M/S
IO 5L
GND
A0L
INTL
63
IO 2L
IO 3L
IO 4L
A1L
VCC
8
GND
IO 0R
IO 1R
9
10
40
39
11
38
INTR
A1R
A2R
IO 2R
12
37
VCC
13
36
A0R
A1R
A3R
A4R
IO 3R
IO 4R
14
15
35
34
A2R
IO 5R
16
33
A4R
30
31
A7R
32
29
BUSYR
A3R
A6R
A5R
28
25
26
A12R
A8R
24
GND
A9R
23
27
22
CER
NC
A11R
A10R
21
SEMR
R/WR
19
20
OER
IO 6R
18
A5R
INTR
A0R
41
CY7C144
17
M/S
BUSYR
A7R
A6R
A
9R
A8R
R/W
R
SEM
R
CER
NC
NC
GND
A12R
A
11R
A10R
47
46
45
44
A5L
A4L
A3L
64
A6L
A8L
A7L
5 4 3 2 1 68 67 66 65 64 63 62 61
60
59
58
57
56
55
54
53
CY7C144/5
52
51
50
49
48
2728 29 30 3132 33 34 35 36 37 38 39 40 41 42 43
IO 7R
21
22
23
24
25
26
NC [3]
OER
IO 3R
IO 4R
IO 5R
IO 6R
10
11
12
13
14
15
16
17
18
19
20
Figure 2. 64-Pin TQFP (Top View)
IO 7R
9 8 7 6
IO 2L
IO 3L
IO 4L
IO 5L
GND
IO 6L
IO 7L
VCC
GND
IO 0R
IO 1R
IO 2R
VCC
NC
NC
VCC
A12L
A
11L
A
10L
A9L
IO 1L
IO 0L
NC [4]
OE L
R/W L
SEM
L
CEL
Figure 1. 68-Pin PLCC (Top View)
R/W L
SEM L
CE L
NC
NC
NC
VCC
A12L
A11L
A10L
A9L
A8L
A7L
A6L
75
74
72
71
70
69
68
67
66
65
64
63
62
61
NC
NC
OE L
76
73
I/O8L
78
77
79
1
I/O1L
I/O0L
NC
I/O 2L
I/O 3L
80
Figure 3. 80-Pin TQFP (Top View)
60
NC
A5L
A4L
2
59
I/O 4L
3
4
58
57
I/O 5L
5
56
A3L
A2L
GND
I/O 6L
6
55
A1L
7
54
A0L
I/O 7L
8
53
V CC
9
10
52
51
11
50
INTL
BUSYL
GND
M/S
12
49
BUSYR
13
48
INTR
14
47
15
16
46
45
A0R
A1R
17
44
I/O 5R
I/O 6R
18
19
43
42
A4R
NC
20
41
NC
37
38
39
40
A6R
A5R
NC
NC
34
A9R
A7R
33
35
36
32
A8R
31
28
NC
NC
A11R
A10R
27
NC
A12R
26
CER
29
30
25
R/WR
SEMR
GND
23
24
22
OER
I/O8R
V CC
I/O 3R
I/O 4R
21
I/O2R
CY7C145
I/O7R
NC
GND
I/O0R
I/O1R
A2R
A3R
NC
Notes:
3. I/O8R on the CY7C145.
4. I/O8L on the CY7C145.
Document #: 38-06034 Rev. *F
Page 2 of 20
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CY7C144, CY7C145
Table 1. Selection Guide
7C144-15
7C145-15
Description
7C144-25
7C145-25
7C144-35
7C145-35
7C144-55
7C145-55
Unit
Maximum Access Time
15
25
35
55
ns
Maximum Operating Current
220
180
160
160
mA
Maximum Standby Current for ISB1
60
40
30
30
mA
Table 2. Pin Definitions
Left Port
Right Port
Description
I/O0L7L(8L) I/O0R7R(8R) Data bus Input/Output
A0L12L
A0R12R
Address Lines
CEL
CER
Chip Enable
OEL
OER
Output Enable
R/WL
R/WR
Read/Write Enable
SEML
SEMR
Semaphore Enable. When asserted LOW, allows access to eight semaphores. The three least significant
bits of the address lines will determine which semaphore to write or read. The I/O0 pin is used when writing
to a semaphore. Semaphores are requested by writing a 0 into the respective location.
INTL
INTR
Interrupt Flag. INTL is set when right port writes location 1FFE and is cleared when left port reads location
1FFE. INTR is set when left port writes location 1FFF and is cleared when right port reads location 1FFF.
BUSYL
BUSYR
Busy Flag
M/S
Master or Slave Select
VCC
Power
GND
Ground
Document #: 38-06034 Rev. *F
Page 3 of 20
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CY7C144, CY7C145
Architecture
The CY7C144/5 consists of a an array of 8K words of 8/9 bits
each of dual-port RAM cells, I/O and address lines, and control
signals (CE, OE, R/W). These control pins permit independent
access for reads or writes to any location in memory. To handle
simultaneous writes or reads to the same location, a BUSY pin
is provided on each port. Two interrupt (INT) pins can be used
for port-to-port communication. Two semaphore (SEM) control
pins are used for allocating shared resources. With the M/S pin,
the CY7C144/5 can function as a Master (BUSY pins are
outputs) or as a slave (BUSY pins are inputs). The CY7C144/5
has an automatic power down feature controlled by CE. Each
port is provided with its own output enable control (OE), which
allows data to be read from the device.
Functional Description
Write Operation
Data must be set up for a duration of tSD before the rising edge
of R/W to guarantee a valid write. A write operation is controlled
by either the OE pin (see Figure 8 on page 11) or the R/W pin
(see Write Cycle No. 2 waveform). Data can be written to the
device tHZOE after the OE is deasserted or tHZWE after the falling
edge of R/W. Required inputs for non-contention operations are
summarized in Table 3.
If a location is being written to by one port and the opposite port
attempts to read that location, a port-to-port flowthrough delay
must be met before the data is read on the output; otherwise the
data read is not deterministic. Data will be valid on the port tDDD
after the data is presented on the other port.
Read Operation
When reading the device, the user must assert both the OE and
CE pins. Data will be available tACE after CE or tDOE after OE are
asserted. If the user of the CY7C144/5 wishes to access a
semaphore flag, then the SEM pin must be asserted instead of
the CE pin.
Interrupts
The interrupt flag (INT) permits communications between
ports.When the left port writes to location 1FFF, the right port’s
interrupt flag (INTR) is set. This flag is cleared when the right port
reads that same location. Setting the left port’s interrupt flag
(INTL) is accomplished when the right port writes to location
1FFE. This flag is cleared when the left port reads location 1FFE.
The message at 1FFF or 1FFE is user-defined. See Table 4 for
input requirements for INT. INTR and INTL are push-pull outputs
and do not require pull-up resistors to operate.
Busy
The CY7C144/5 provides on-chip arbitration to alleviate simultaneous memory location access (contention). If both ports’ CEs
are asserted and an address match occurs within tPS of each
other the Busy logic determines which port has access. If tPS is
violated, one port will definitely gain permission to the location,
but it is not guaranteed which one. BUSY will be asserted tBLA
after an address match or tBLC after CE is taken LOW. BUSYL
and BUSYR in master mode are push-pull outputs and do not
require pull-up resistors to operate.
Document #: 38-06034 Rev. *F
Master/Slave
An M/S pin is provided in order to expand the word width by
configuring the device as either a master or a slave. The BUSY
output of the master is connected to the BUSY input of the slave.
This enables the device to interface to a master device with no
external components.Writing of slave devices must be delayed
until after the BUSY input has settled. Otherwise, the slave chip
may begin a write cycle during a contention situation.When
presented a HIGH input, the M/S pin allows the device to be used
as a master and therefore the BUSY line is an output. BUSY can
then be used to send the arbitration outcome to a slave.
Semaphore Operation
The CY7C144/5 provides eight semaphore latches which are
separate from the dual-port memory locations. Semaphores are
used to reserve resources that are shared between the two
ports.The state of the semaphore indicates that a resource is in
use. For example, if the left port wants to request a given
resource, it sets a latch by writing a 0 to a semaphore location.
The left port then verifies its success in setting the latch by
reading it. After writing to the semaphore, SEM or OE must be
deasserted for tSOP before attempting to read the semaphore.
The semaphore value is available tSWRD + tDOE after the rising
edge of the semaphore write. If the left port was successful
(reads a 0), it assumes control over the shared resource,
otherwise (reads a 1) it assumes the right port has control and
continues to poll the semaphore.When the right side has relinquished control of the semaphore (by writing a 1), the left side
will succeed in gaining control of the semaphore. If the left side
no longer requires the semaphore, a 1 is written to cancel its
request.
Semaphores are accessed by asserting SEM LOW. The SEM
pin functions as a chip enable for the semaphore latches (CE
must remain HIGH during SEM LOW). A0–2 represents the
semaphore address. OE and R/W are used in the same manner
as a normal memory access.When writing or reading a
semaphore, the other address pins have no effect.
When writing to the semaphore, only I/O0 is used. If a 0 is written
to the left port of an unused semaphore, a 1 appears at the same
semaphore address on the right port. That semaphore can now
only be modified by the side showing 0 (the left port in this case).
If the left port now relinquishes control by writing a 1 to the
semaphore, the semaphore will be set to 1 for both sides.
However, if the right port had requested the semaphore (written
a 0) while the left port had control, the right port would immediately own the semaphore as soon as the left port released it.
Table 5 shows sample semaphore operations.
When reading a semaphore, all eight/nine data lines output the
semaphore value. The read value is latched in an output register
to prevent the semaphore from changing state during a write
from the other port. If both ports attempt to access the
semaphore within tSPS of each other, the semaphore is definitely
obtained by one side or the other, but there is no guarantee which
side controls the semaphore.
Initialization of the semaphore is not automatic and must be reset
during initialization program at power up. All Semaphores on
both sides should have a one written into them at initialization
from both sides to assure that they are free when needed.
Page 4 of 20
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CY7C144, CY7C145
Table 3. Non-Contending Read/Write
Inputs
Outputs
Operation
CE
R/W
OE
SEM
H
X
X
H
High Z
Power Down
H
H
L
L
Data Out
Read Data in Semaphore
X
X
H
X
High Z
I/O Lines Disabled
X
L
Data In
Write to Semaphore
H
L
H
Data Out
Read
L
L
X
H
Data In
Write
L
X
X
L
H
L
I/O07/8
Illegal Condition
Table 4. Interrupt Operation Example (assumes BUSYL = BUSYR = HIGH)
Function
Left Port
Right Port
R/W
CE
OE
A012
INT
R/W
CE
OE
A012
INT
Set Left INT
X
X
X
X
L
L
L
X
1FFE
X
Reset Left INT
X
L
L
1FFE
H
X
L
L
X
X
Set Right INT
L
L
X
1FFF
X
X
X
X
X
L
Reset Right INT
X
X
X
X
X
X
L
L
1FFF
H
Table 5. Semaphore Operation Example
Function
I/O0-7/8 Left
I/O0-7/8 Right
Status
No action
1
1
Semaphore free
Left port writes semaphore
0
1
Left port obtains semaphore
Right port writes 0 to semaphore
0
1
Right side is denied access
Left port writes 1 to semaphore
1
0
Right port is granted access to semaphore
Left port writes 0 to semaphore
1
0
No change. Left port is denied access
Right port writes 1 to semaphore
0
1
Left port obtains semaphore
Left port writes 1 to semaphore
1
1
No port accessing semaphore address
Right port writes 0 to semaphore
1
0
Right port obtains semaphore
Right port writes 1 to semaphore
1
1
No port accessing semaphore
Left port writes 0 to semaphore
0
1
Left port obtains semaphore
Left port writes 1 to semaphore
1
1
No port accessing semaphore
Document #: 38-06034 Rev. *F
Page 5 of 20
[+] Feedback
CY7C144, CY7C145
Maximum Ratings
Exceeding maximum ratings may impair the useful life of the
device. These user guidelines are not tested.[5]
Storage Temperature 65C to +150C
Ambient Temperature with
Power Applied 55C to +125C
Output Current into Outputs (LOW)............................. 20 mA
Static Discharge Voltage........................................... >2001V
(per MIL-STD-883, Method 3015)
Latch Up Current .................................................... >200 mA
Operating Range
Supply Voltage to Ground Potential 0.5V to +7.0V
DC Voltage Applied to Outputs
in High Z State 0.5V to +7.0V
DC Input Voltage[6] 0.5V to +7.0V
Ambient
Temperature
VCC
0C to +70C
5V 10%
40C to +85C
5V 10%
Range
Commercial
Industrial
Electrical Characteristics
Over the Operating Range
Parameter
Description
7C144-15
7C145-15
Test Conditions
Min
VOH
Output HIGH Voltage
VCC = Min., IOH = 4.0 mA
VOL
Output LOW Voltage
VCC = Min., IOL = 4.0 mA
VIH
Input HIGH Voltage
VIL
Input LOW Voltage
Max
2.4
7C144-25
7C145-25
Min
2.4
0.4
2.2
V
0.4
2.2
0.8
Unit
Max
V
V
0.8
V
IIX
Input Leakage Current
GND < VI < VCC
10
+10
10
+10
A
IOZ
Output Leakage Current
Outputs Disabled, GND < VO < VCC
10
+10
10
+10
A
ICC
Operating Current
VCC = Max., IOUT = 0 mA
Outputs Disabled
Commercial
180
mA
Standby Current
(Both Ports TTL Levels)
CEL and CER > VIH,
f = fMAX[7]
Commercial
ISB2
Standby Current
(One Port TTL Level)
CEL or CER > VIH,
f = fMAX[7]
Commercial
ISB3
Standby Current
Both Ports
(Both Ports CMOS Levels) CE and CER > VCC – 0.2V,
VIN > VCC – 0.2V
or VIN < 0.2V, f = 0[7]
Commercial
Standby Current
(One Port CMOS Level)
Commercial
ISB1
ISB4
One Port
CEL or CER > VCC – 0.2V,
VIN > VCC – 0.2V or
VIN < 0.2V, Active
Port Outputs, f = fMAX[7]
220
Industrial
190
60
Industrial
130
Industrial
mA
110
mA
120
15
Industrial
Industrial
40
50
15
mA
30
125
100
mA
115
Notes
5. The Voltage on any input or I/O pin cannot exceed the power pin during power up.
6. Pulse width < 20 ns.
7. fMAX = 1/tRC = All inputs cycling at f = 1/tRC (except output enable). f = 0 means no address or control lines change. This applies only to inputs at CMOS level standby ISB3
Document #: 38-06034 Rev. *F
Page 6 of 20
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CY7C144, CY7C145
Electrical Characteristics
Over the Operating Range (continued)
Parameter
Description
7C144-35
7C145-35
Test Conditions
Min
7C144-55
7C145-55
Max
Min
Unit
Max
VOH
Output HIGH Voltage
VCC = Min., IOH = 4.0 mA
VOL
Output LOW Voltage
VCC = Min., IOL = 4.0 mA
VIH
Input HIGH Voltage
VIL
Input LOW Voltage
0.8
V
IIX
Input Leakage Current
GND < VI < VCC
10
+10
10
+10
A
IOZ
Output Leakage Current
Outputs Disabled, GND < VO < VCC
10
+10
10
+10
A
ICC
Operating Current
VCC = Max., IOUT = 0 mA
Outputs Disabled
Commercial
160
160
mA
Industrial
180
180
ISB1
Standby Current
(Both Ports TTL Levels)
CEL and CER > VIH,
f = fMAX[7]
Commercial
30
30
Industrial
40
40
ISB2
Standby Current
(One Port TTL Level)
CEL or CER > VIH,
f = fMAX[7]
Commercial
100
100
Industrial
110
110
ISB3
Standby Current
Both Ports
(Both Ports CMOS Levels) CE and CER > VCC – 0.2V,
VIN > VCC – 0.2V
or VIN < 0.2V, f = 0[7]
Commercial
15
15
Industrial
30
30
Standby Current
(One Port CMOS Level)
Commercial
90
90
Industrial
100
100
ISB4
2.4
2.4
0.4
0.4
2.2
V
2.2
0.8
One Port
CEL or CER > VCC – 0.2V,
VIN > VCC – 0.2V or
VIN < 0.2V, Active
Port Outputs, f = fMAX[7]
V
V
mA
mA
mA
mA
Capacitance
Tested initially and after any design or process changes that may affect these parameters.
Parameter
Description
CIN
Input Capacitance
COUT
Output Capacitance
Test Conditions
Max.
TA = 25C, f = 1 MHz,
VCC = 5.0V
Unit
10
pF
15
pF
Figure 4. AC Test Loads and Waveforms
5V
5V
R1 = 893
R1 = 893
RTH = 250
OUTPUT
OUTPUT
OUTPUT
C = 30 pF
C = 5 pF
C = 30pF
R2 = 347
R = 347
VTH = 1.4V
(b) Thévenin Equivalent (Load 1)
(a) Normal Load (Load1)
(c) Three-State Delay (Load 3)
ALL INPUT PULSES
OUTPUT
3.0V
C = 30 pF
GND
10%
3 ns
90%
90%
10%
3 ns
Load (Load 2)
Document #: 38-06034 Rev. *F
Page 7 of 20
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CY7C144, CY7C145
Switching Characteristics
Over the Operating Range[8]
Parameter
Description
7C144-15
7C145-15
Min
Max
7C144-25
7C145-25
Min
Max
7C144-35
7C145-35
Min
Max
7C144-55
7C145-55
Min
Unit
Max
READ CYCLE
tRC
Read Cycle Time
tAA
Address to Data Valid
tOHA
Output Hold From Address
Change
tACE
CE LOW to Data Valid
15
25
35
55
ns
OE LOW to Data Valid
10
15
20
25
ns
tDOE
tLZOE
[9, 10,11]
OE Low to Low Z
[9, 10,11]
OE HIGH to High Z
tHZOE
tLZCE[9, 10,11]
tHZCE
[9, 10,11]
CE LOW to Low Z
15
15
3
tPU
CE LOW to Power-Up
tPD
[11]
CE HIGH to Power-Down
35
25
3
3
10
0
35
15
0
15
55
20
0
25
ns
25
3
20
ns
ns
25
0
35
ns
ns
3
3
15
ns
3
3
3
10
55
3
3
3
CE HIGH to High Z
[11]
25
ns
ns
55
ns
WRITE CYCLE
tWC
Write Cycle Time
15
25
35
55
ns
tSCE
CE LOW to Write End
12
20
30
45
ns
tAW
Address Set-Up to Write End
12
20
30
45
ns
tHA
Address Hold From Write End
2
2
2
2
ns
tSA
Address Set-Up to Write Start
0
0
0
0
ns
tPWE
Write Pulse Width
12
20
25
40
ns
tSD
Data Set-Up to Write End
10
15
15
25
ns
tHD
Data Hold From Write End
0
0
0
0
ns
[10,11]
R/W LOW to High Z
[10,11]
R/W HIGH to Low Z
tHZWE
tLZWE
tWDD
[12]
tDDD[12]
10
3
15
3
20
3
25
3
ns
ns
Write Pulse to Data Delay
30
50
60
70
ns
Write Data Valid to Read Data
Valid
25
30
35
40
ns
Notes
8. Test conditions assume signal transition time of 3 ns or less, timing reference levels of 1.5V, input pulse levels of 0 to 3.0V, and output loading of the specified IOI/IOH
and 30-pF load capacitance.
9. At any given temperature and voltage condition for any given device, tHZCE is less than tLZCE and tHZOE is less than tLZOE.
10. Test conditions used are Load 3.
11. This parameter is guaranteed but not tested.
12. For information on part-to-part delay through RAM cells from writing port to reading port, refer to Read Timing with Port-to-Port Delay waveform.
Document #: 38-06034 Rev. *F
Page 8 of 20
[+] Feedback
CY7C144, CY7C145
Switching Characteristics
Over the Operating Range
Parameter
(continued)
[8]
Description
7C144-15
7C145-15
Min
Max
7C144-25
7C145-25
Min
Max
7C144-35
7C145-35
Min
Max
7C144-55
7C145-55
Min
Unit
Max
BUSY TIMING[13]
tBLA
BUSY LOW from Address
Match
15
20
20
30
ns
tBHA
BUSY HIGH from Address
Mismatch
15
20
20
30
ns
tBLC
BUSY LOW from CE LOW
15
20
20
30
ns
tBHC
BUSY HIGH from CE HIGH
15
20
20
30
ns
tPS
Port Set-Up for Priority
5
5
5
5
ns
tWB
R/W LOW after BUSY LOW
0
0
0
0
ns
tWH
R/W HIGH after BUSY HIGH
13
20
30
30
ns
tBDD
BUSY HIGH to Data Valid
15
25
35
55
ns
[13]
INTERRUPT TIMING
tINS
INT Set Time
15
25
25
35
ns
tINR
INT Reset Time
15
25
25
35
ns
SEMAPHORE TIMING
tSOP
SEM Flag Update Pulse (OE or
SEM)
10
10
15
20
ns
tSWRD
SEM Flag Write to Read Time
5
5
5
5
ns
tSPS
SEM Flag Contention
Window
5
5
5
5
ns
Note
13. Test conditions used are Load 2.
Document #: 38-06034 Rev. *F
Page 9 of 20
[+] Feedback
CY7C144, CY7C145
Switching Waveforms
Figure 5. Read Cycle No. 1 (Either Port Address Access)[14, 15]
tRC
ADDRESS
tAA
tOHA
DATA OUT
PREVIOUS DATA VALID
DATA VALID
Figure 6. Read Cycle No. 2 (Either Port CE/OE Access)[14, 16, 17]
SEM or CE
tHZCE
tACE
OE
tLZOE
tHZOE
tDOE
tLZCE
DATA VALID
DATA OUT
tPU
tPD
ICC
ISB
Figure 7. Read Timing with Port-to-Port Delay (M/S=L)[18, 19]
tWC
ADDRESSR
MATCH
t
R/WR
PWE
t
DATAIN R
ADDRESSL
t
SD
HD
VALID
MATCH
tDDD
DATA OUTL
VALID
tWDD
Notes
14. R/W is HIGH for read cycle.
15. Device is continuously selected CE = LOW and OE = LOW. This waveform cannot be used for semaphore reads.
16. Address valid prior to or coincident with CE transition LOW.
17. CEL = L, SEM = H when accessing RAM. CE = H, SEM = L when accessing semaphores.
18. BUSY = HIGH for the writing port.
19. CEL = CER = LOW.
Document #: 38-06034 Rev. *F
Page 10 of 20
[+] Feedback
CY7C144, CY7C145
Switching Waveforms
(continued)
Figure 8. Write Cycle No. 1: OE Three-State Data I/Os (Either Port)[20, 21, 22]
tWC
ADDRESS
tSCE
SEM OR CE
tHA
tAW
tPWE
R/W
tSA
tSD
DATA IN
tHD
DATA VALID
OE
t
tHZOE
LZOE
HIGH IMPEDANCE
DATA OUT
Figure 9. Write Cycle No. 2: R/W Three-State Data I/Os (Either Port)[20, 22, 23]
tWC
ADDRESS
tSCE
tHA
SEM OR CE
R/W
tSA
tAW
tPWE
tSD
DATAVALID
DATA IN
tHZWE
DATA OUT
tHD
tLZWE
HIGH IMPEDANCE
Notes
20. The internal write time of the memory is defined by the overlap of CE or SEM LOW and R/W LOW. Both signals must be LOW to initiate a write, and either signal can
terminate a write by going HIGH. The data input set-up and hold timing should be referenced to the rising edge of the signal that terminates the write.
21. If OE is LOW during a R/W controlled write cycle, the write pulse width must be the larger of tPWE or (tHZWE + tSD) to allow the I/O drivers to turn off and data to be
placed on the bus for the required tSD. If OE is HIGH during a R/W controlled write cycle (as in this example), this requirement does not apply and the write pulse can
be as short as the specified tPWE.
22. R/W must be HIGH during all address transitions.
23. Data I/O pins enter high impedance when OE is held LOW during write.
Document #: 38-06034 Rev. *F
Page 11 of 20
[+] Feedback
CY7C144, CY7C145
Switching Waveforms
(continued)
Figure 10. Semaphore Read After Write Timing, Either Side[24]
tOHA
tAA
A0A 2
VALID ADDRESS
VALID ADDRESS
tAW
tACE
tHA
SEM
tSCE
tSOP
tSD
I/O0
DATA IN VALID
tSA
DATA OUT VALID
tHD
tPWE
R/W
tSWRD
tDOE
tSOP
OE
WRITE CYCLE
READ CYCLE
Figure 11. Semaphore Contention[25, 26, 27]
A0LA 2L
MATCH
R/WL
SEML
tSPS
A0RA 2R
MATCH
R/WR
SEM R
Notes
24. CE = HIGH for the duration of the above timing (both write and read cycle).
25. I/O0R = I/O0L = LOW (request semaphore); CER = CEL = HIGH
26. Semaphores are reset (available to both ports) at cycle start.
27. If tSPS is violated, the semaphore will definitely be obtained by one side or the other, but there is no guarantee which side will control the semaphore.
Document #: 38-06034 Rev. *F
Page 12 of 20
[+] Feedback
CY7C144, CY7C145
Switching Waveforms
(continued)
Figure 12. Read with BUSY (M/S=HIGH)[19]
tWC
ADDRESSR
MATCH
tPWE
R/WR
tSD
DATAINR
tHD
VALID
tPS
ADDRESSL
MATCH
tBLA
tBHA
BUSYL
tBDD
tDDD
DATA OUTL
VALID
tWDD
Figure 13. Write Timing with Busy Input (M/S=LOW)
tPWE
R/W
BUSY
Document #: 38-06034 Rev. *F
tWB
tWH
Page 13 of 20
[+] Feedback
CY7C144, CY7C145
Switching Waveforms
(continued)
Figure 14. Busy Timing Diagram No. 1 (CE Arbitration)[28]
CEL Valid First:
ADDRESSL,R
ADDRESS MATCH
CEL
tPS
CER
tBLC
tBHC
BUSYR
CER Valid First:
ADDRESSL,R
ADDRESS MATCH
CER
tPS
CEL
tBLC
tBHC
BUSYL
Figure 15. Busy Timing Diagram No. 2 (Address Arbitration)[28]
Left Address Valid First:
tRC or tWC
ADDRESS L
ADDRESS MATCH
ADDRESS MISMATCH
tPS
ADDRESS R
tBLA
tBHA
BUSY R
Right Address Valid First:
tRC or tWC
ADDRESS R
ADDRESS MATCH
ADDRESS MISMATCH
tPS
ADDRESS L
tBLA
tBHA
BUSYL
Note
28. If tPS is violated, the busy signal will be asserted on one side or the other, but there is no guarantee on which side BUSY will be asserted.
Document #: 38-06034 Rev. *F
Page 14 of 20
[+] Feedback
CY7C144, CY7C145
Switching Waveforms
(continued)
Figure 16. Interrupt Timing Diagrams
Left Side Sets INTR:
ADDRESS L
tWC
WRITE 1FFF
tHA [29]
CE L
R/W L
INT R
tINS [30]
Right Side Clears INTR:
tRC
ADDRESS R
READ 1FFF
CER
tINR [30]
R/WR
OE R
INTR
Right Side Sets INTL:
ADDRESS R
tWC
WRITE 1FFE
tHA [29]
CE R
R/W R
INT L
tINS [30]
Left Side Clears INTL:
tRC
ADDRESS R
READ 1FFE
CEL
tINR[30]
R/WL
OEL
INTL
Notes
29. tHA depends on which enable pin (CEL or R/WL) is deasserted first.
30. tINS or tINR depends on which enable pin (CEL or R/WL) is asserted last.
Document #: 38-06034 Rev. *F
Page 15 of 20
[+] Feedback
CY7C144, CY7C145
ICC
1.0
ISB3
0.8
0.6
0.4
0.2
0.0
4.0
4.5
5.0
5.5
ICC
1.0
ISB3
0.8
0.6
VCC = 5.0V
VIN = 5.0V
0.4
0.2
0.6
55
6.0
NORMALIZED ACCESS TIME
vs. AMBIENT TEMPERATURE
NORMALIZED ACCESS TIME
vs. SUPPLY VOLTAGE
1.4
1.6
1.3
1.4
NORMALIZED tAA
1.2
1.1
TA = 25°C
1.2
1.0
VCC = 5.0V
0.8
0.9
0.8
4.0
4.5
5.0
5.5
0.6
55
6.0
AMBIENT TEMPERATURE (°C)
TYPICAL POWER-ON CURRENT
vs. SUPPLY VOLTAGE
TYPICAL ACCESS TIME CHANGE
vs. OUTPUT LOADING
30.0
DELTA tAA (ns)
NORMALIZED tPC
25.0
0.75
20.0
15.0
0.50
0.25
VCC = 4.5V
TA = 25°C
5.0
1.0
2.0
3.0
4.0
SUPPLY VOLTAGE (V)
Document #: 38-06034 Rev. *F
120
VCC = 5.0V
TA = 25°C
80
40
0
0
5.0
0
1.0
2.0
3.0
4.0
5.0
OUTPUT VOLTAGE (V)
140
OUTPUT SINK CURRENT
vs. OUTPUT VOLTAGE
120
100
80
60
40
VCC = 5.0V
TA = 25°C
20
0
0.0
1.0
2.0
3.0
4.0
5.0
OUTPUT VOLTAGE (V)
1.25
NORMALIZED ICC vs. CYCLE TIME
1.0
VCC = 5.0V
TA = 25°C
VIN = 5.0V
0.75
10.0
0
160
125
25
SUPPLY VOLTAGE (V)
1.00
0.0
200
NORMALIZED ICC
NORMALIZED tAA
125
OUTPUT SOURCE CURRENT
vs. OUTPUT VOLTAGE
AMBIENT TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
1.0
25
OUTPUT SINK CURRENT (mA)
1.2
1.2
NORMALIZED ICC, ISB
NORMALIZED ICC, ISB
1.4
NORMALIZED SUPPLY CURRENT
vs. AMBIENT TEMPERATURE
NORMALIZED SUPPLY CURRENT
vs. SUPPLY VOLTAGE
OUTPUT SOURCE CURRENT (mA)
Figure 17. Typical DC and AC Characteristics
0
200
400
600
800 1000
CAPACITANCE (pF)
0.50
10
28
40
66
CYCLE FREQUENCY (MHz)
Page 16 of 20
[+] Feedback
CY7C144, CY7C145
Ordering Information
8K x8 Dual-Port SRAM
Speed
(ns)
15
25
55
Ordering Code
Package
Diagram
Package Type
CY7C144-15AXC
51-85046
64-Pin Thin Quad Flat Pack (Pb-Free)
CY7C144-15JXI
51-85005
68-Pin Plastic Leaded Chip Carrier (Pb-Free)
CY7C144-15AXI
51-85046
64-Pin Thin Quad Flat Pack (Pb-Free)
CY7C144-25AC
51-85046
64-Pin Thin Quad Flat Pack
CY7C144-25AXC
51-85046
64-Pin Thin Quad Flat Pack (Pb-Free)
CY7C144-55AC
51-85046
64-Pin Thin Quad Flat Pack
CY7C144-55AXC
51-85046
64-Pin Thin Quad Flat Pack (Pb-Free)
CY7C144-55JC
51-85005
68-Pin Plastic Leaded Chip Carrier
CY7C144-55JXC
51-85005
68-Pin Plastic Leaded Chip Carrier (Pb-Free)
51-85065
80-Pin Thin Quad Flat Pack (Pb-Free)
Operating
Range
Commercial
Industrial
Commercial
Commercial
8K x9 Dual-Port SRAM
15
CY7C145-15AXC
Commercial
Package Diagrams
Figure 18. 64-Pin Thin Plastic Quad Flat Pack (14 x 14 x 1.4 mm), 51-85046
51-85046 *D
Document #: 38-06034 Rev. *F
Page 17 of 20
[+] Feedback
CY7C144, CY7C145
Package Diagrams
(continued)
Figure 19. 80-Pin Thin Plastic Quad Flat Pack, 51-85065
51-85065 *C
Figure 20. 68-Pin Plastic Leaded Chip Carrier, 51-85005
51-85005 *B
Document #: 38-06034 Rev. *F
Page 18 of 20
[+] Feedback
CY7C144, CY7C145
Document History Page
Document Title: CY7C145, CY7C144 8K x 8/9 Dual-Port Static RAM with Sem, Int, Busy
Document Number: 38-06034
Rev.
ECN No.
Orig. of
Change
Submission Description of Change
Date
**
110175
SZV
09/29/01
Change from Spec number: 38-00163 to 38-06034
*A
122285
RBI
12/27/02
Power up requirements added to Maximum Ratings Information
*B
236752
YDT
See ECN
Removed cross information from features section, added CY7C144-15AI to
ordering information section
*C
393320
YIM
See ECN
Added Pb-Free Logo
Added Pb-Free parts to ordering information:
CY7C144-15AXC, CY7C144-15JXC, CY7C144-15AXI, CY7C144-25AXC,
CY7C144-55AXC, CY7C144-55JXC, CY7C145-15AXC, CY7C145-35JXC
*D
2623658
VKN/PYRS
12/17/2008 Added CY7C144-15JXI in the Ordering information table
*E
2699693
VKN/PYRS
04/29/2009 Corrected defective Logic Block diagram, Pinouts and Package diagrams
*F
2896210
RAME
Document #: 38-06034 Rev. *F
03/22/2010 Updated Ordering Information
Updated Package Diagrams
Page 19 of 20
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CY7C144, CY7C145
Sales, Solutions and Legal Information
Worldwide Sales and Design Support
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© Cypress Semiconductor Corporation, 2005-2010. 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 product. Nor does it convey or imply any license under patent or other rights. Cypress products are not warranted nor intended to be used
for medical, life support, life saving, critical control or safety applications, unless pursuant to an express written agreement with Cypress. Furthermore, Cypress 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 products in life-support
systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges.
Any Source Code (software and/or firmware) is owned by Cypress Semiconductor Corporation (Cypress) and is protected by and subject to worldwide patent protection (United States and foreign),
United States copyright laws and international treaty provisions. Cypress hereby grants to licensee a personal, non-exclusive, non-transferable license to copy, use, modify, create derivative works of,
and compile the Cypress Source Code and derivative works for the sole purpose of creating custom software and or firmware in support of licensee product to be used only in conjunction with a Cypress
integrated circuit as specified in the applicable agreement. Any reproduction, modification, translation, compilation, or representation of this Source Code except as specified above is prohibited without
the express written permission of Cypress.
Disclaimer: CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress reserves the right to make changes without further notice to the materials described herein. Cypress does not
assume any liability arising out of the application or use of any product or circuit described herein. Cypress 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’ product in a life-support systems application implies that the manufacturer
assumes all risk of such use and in doing so indemnifies Cypress against all charges.
Use may be limited by and subject to the applicable Cypress software license agreement.
Document #: 38-06034 Rev. *F
Revised March 22, 2010
Page 20 of 20
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