CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
3.3V 32K/64K x 16/18 Dual-Port Static
RAM
Cypress Semiconductor Corporation • 198 Champion Court • San Jose
,
CA 95134-1709 • 408-943-2600
Document #: 38-06078 Rev. *B Revised December 09, 2008
Features
■
True Dual-Ported memory cells which allow
simultaneous access of the same memory location
■
32K x 16 organization (CY7C027V/027VN/027AV
[1]
)
■
64K x 16 organizati on (CY7C028V)
■
32K x 18 organization (CY7C037V/037AV
[2]
)
■
64K x 18 organizati on (CY7C038V)
■
0.35 micron CMOS for optimum speed and power
■
High speed access: 15, 20, and 25 ns
■
Low operating power
■
Active: I
CC
= 115 mA (typical)
■
Standby: I
SB3
= 10 μA (typical)
■
Fully asynchronous operation
■
Automatic power down
■
Expandable data bus to 32/36 bits or more using Master/Slave
chip select when using more than one device
■
On-chip arbitration logic
■
Semaphores included to permit software handshaking
between ports
■
INT flag for port-to-port communication
■
Separate upper-byte and lower-byte control
■
Dual chip enables
■
Pin select for Master or Slave
■
Commercial and Industrial temperature ranges
■
100-pin Pb-free TQFP and 100-pin TQFP
Notes
1. CY7C027V, CY7C027VN and CY7C027AV are functionally identical.
2. CY7C037V and CY7C037AV are functionally identical.
3. I/O
8
–I/O
15
for x16 devices; I/O
9
–I/O
17
for x18 devices.
4. I/O
0
–I/O
7
for x16 devices; I/O
0
–I/O
8
for x18 devices.
5. A
0
–A
14
for 32K; A
0
–A
15
for 64K devices.
6. BUSY is an output in master mode and an input in slave mode.
R/W
L
CE
0L
CE
1L
OE
L
I/O
8/9L
–I/O
15/17L
I/O
Control
Address
Decode
A
0L
–A
14/15L
CE
L
OE
L
R/W
L
BUSY
L
I/O
Control
CE
L
Interrupt
Semaphore
Arbitration
SEM
L
INT
L
M/S
UB
L
LB
L
I/O
0L
–I/O
7/8L
R/W
R
CE
0R
CE
1R
OE
R
I/O
8/9L
–I/O
15/17R
CE
R
UB
R
LB
R
I/O
0L
–I/O
7/8R
UB
L
LB
L
Logic Block Diagram
A
0L
–A
14/15L
True Dual-Ported
RAM Array
A
0R
–A
14/15R
CE
R
OE
R
R/W
R
BUSY
R
SEM
R
INT
R
UB
R
LB
R
Address
Decode A
0R
–A
14/15R
[3] [3]
[4] [4]
[5] [5]
[6] [6]
[5] [5]
15/16
8/9
8/9
15/16
8/9
8/9
15/16 15/16
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 2 of 18
Pin Configurations
Figure 1. 100-Pin TQFP (Top View)
1
3
2
92 91 90 848587 868889 83 82 81 7678 77798093949596979899100
59
60
61
67
66
64
65
63
62
68
69
70
75
73
74
72
71
A9R
A10R
A11R
A12R
A13R
A14R
UBR
NC
LBR
CE1R
SEMR
OER
GND
NC
A15R
GND
R/WR
GND
I/O15R
I/O14R
I/O13R
I/O12R
I/O11R
I/O10R
CE0R
58
57
56
55
54
53
52
51
CY7C027V/027VN/027AV (32K x 16)
A9L
A10L
A11L
A12L
A13L
A14L
UBL
NC
LBL
CE1L
SEML
OEL
GND
NC
A15L
VCC
R/WL
GND
I/O15L
I/O14L
I/O13L
I/O12L
I/O11L
I/O10L
CE0L
17
16
15
9
10
12
11
13
14
8
7
6
4
5
18
19
20
21
22
23
24
25
A8L
A7L
A6L
A5L
A4L
A3L
INTL
A1L
NC
GND
M/S
A0R
A1R
A0L
A2L
BUSYR
INTR
A2R
A3R
A4R
A5R
A6R
A7R
A8R
BUSYL
34 35 36 424139 403837 43 44 45 5048 494746
NC
I/O9R
I/O8R
I/O7R
VCC
I/O6R
I/01R
I/O4R
I/O2R
GND
I/O0L
I/O2L
I/O3L
I/O3R
I/O5R
I/O1L
GND
I/O4L
I/O5L
I/O6L
I/O7L
VCC
I/O8L
I/O9L
I/O0R
3332313029282726
CY7C028V (64K x 16)
[1] [1]
Note
1. This pin is NC for CY7C027V/027VN/027AV.
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 3 of 18
Pin Configurations
(continued)
Figure 2. 100-Pin TQFP (Top View)
1
3
2
92 91 90 848587 868889 83 82 81 7678 77798093949596979899100
59
60
61
67
66
64
65
63
62
68
69
70
75
73
74
72
71
A8R
A9R
A10R
A11R
A12R
A13R
CE0R
A15R
UBR
SEMR
R/WR
GND
I/O17R
LBR
A14R
GND
OER
GND
I/O16R
I/O15R
I/O14R
I/O13R
I/O12R
I/O11R
CE1R
58
57
56
55
54
53
52
51
CY7C037V/037AV (32K x 18)
A9L
A10L
A11L
A12L
A13L
A14L
CE1L
LBL
CE0L
R/WL
OEL
I/O17L
I/O16L
UBL
A15L
VCC
GND
GND
I/O15L
I/O14L
I/O13L
I/O12L
I/O11L
I/O10L
SEML
17
16
15
9
10
12
11
13
14
8
7
6
4
5
18
19
20
21
22
23
24
25
A8L
A7L
A6L
A5L
A4L
A3L
BUSYL
A1L
INTL
GND
VCC
INTR
A0R
A0L
A2L
M/S
BUSYR
A1R
A2R
A3R
A4R
A5R
A6R
A7R
GND
34 35 36 424139 403837 43 44 45 5048 494746
I/O10R
I/O9R
I/O8R
I/O7R
VCC
I/O6R
I/01R
I/O4R
I/O2R
GND
I/O0L
I/O2L
I/O3L
I/O3R
I/O5R
I/O1L
GND
I/O4L
I/O5L
I/O6L
I/O7L
VCC
I/O8L
I/O9L
I/O0R
3332313029282726
CY7C038V (64K x 18)
[2]
[2]
Selection Guide
Parameter -15 -20 -25 Unit
Maximum Access Time 15 20 25 ns
Typical Operating Current 125 120 115 mA
Typical S tandby Current for I
SB1
(Both ports TTL level) 35 35 30 mA
Typical S tandby Current for I
SB3
(Both ports CMOS level) 10 μA10 μA10 μAμA
Note
2. This pin is NC for CY7C037V/037AV.
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 4 of 18
Architecture
The CY7C027V/027VN/027AV/028V and
CY7037V/037A V/038V consist of an array of 32K and 64K words
of 16 and 18 bits each of dual-port RAM cells, I/O and addre ss
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 simult ane ous wri tes/reads t o the sa me locatio n, a BU SY pin is
provided on each port. Two interrupt (INT) pins can be utilized for
port-to-port communication. Two semaphore (SEM) control pins are
used for allocating shared resources. With the M/S pin, the devices can
function as a master (BUSY pins are outputs) or as a slave (BUSY pins
are inputs). The devices also have an automatic power down feature
controlled by CE. Each port is provided with its own output enable
control (OE), which allows dat a to be read from the device.
Functional Description
The CY7C027V/027VN/027AV/028V and
CY7037V/037AV/038V are low power CMOS 32K, 64 K x 16/18
dual-port static RAMs. Various arbitration schemes are included
on the devices to handle situations when multiple processors
access the same piece o f data. Two ports are provided , permit-
ting independent, asynchronous access for reads and writes to
any location in memory. The devices can be utilized as
stand-alone 16/18-bit dual-port static RAMs or multiple devices
can be combined to function as a 32/36-bit or wider master/slave
dual-port static RAM. An M/S pin is provided for implementing
32/36-bit or wider memory applications without the need for sep-
arate master and slave devices or additional discrete log ic. Ap-
plication areas include interprocessor/multiprocessor designs,
communications status buffering, and dual-port video/graphics
memory.
Each port has independent co ntrol pins : chip enable (CE), read
or write enable (R / W ), and output enable (OE). Two flags are provided
on each port (BUSY and INT). BUSY signals that the port is trying to
access the same location currently being accessed by the ot her 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 semaph ore indicates that a share d re sou rce is in use. An
automatic power down feature is controlled independently on each port
by a chip select ( CE) pin.
The CY7C027V/027VN/027AV/028V and
CY7037V/037A V/038V are available in 100-pin Thin Quad Plas-
tic Flatpacks (TQFP).
Write Operation
Data must be set up for a duration of t
SD
before the risin g edge of
R/W to guarantee a valid write. A write operation is controll ed by either
the R/W pin (see Figure 7) or the CE pin (see Figure 8). Required inputs
for non-contention op erations are summarized in Table 1.
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 occur before the da ta is read on the output; o therwise the
data read is not deterministic. D ata is valid on the port t
DDD
after
the data is presented on the other port.
Read Operation
When reading the device, the user mu st assert both the OE and
CE pins. Data is available t
ACE
after CE or t
DOE
after OE is asserted. If
the user wishes to access a semaphore flag, then the SEM pin must be
asserted instead of the CE pin, and OE must also be asserted.
Interrupts
The upper two memory locations may be used for message
passing. The highest memory location (7FFF for the
CY7C027V/027VN/027A V/37V , FFFF for the CY7C028V/38V) is
the mailbox for the right port and the second-highest memory
location (7FFE for the CY7C027V/027VN/027AV/037V/037AV,
FFFE for the CY7C028V/38V) is the mailbox for the left port.
When one port write s to the other po rt’s mailbox, an interrupt is
Pin Definitions
Left Port Right Port Description
CE
0L
, CE
1L
CE
0R
, CE
1R
Chip Enable (CE is LOW when CE
0
≤ V
IL
and CE
1
≥ V
IH
)
R/W
L
R/W
R
Read/Write Enable
OE
L
OE
R
Output Enable
A
0L
–A
15L
A
0R
–A
15R
Address (A
0
–A
14
for 32K; A
0
–A
15
for 64K devices)
I/O
0L
–I/O
17L
I/O
0R
–I/O
17R
Data Bus Input/Output (I/O
0
–I/O
15
for x16 devices; I/O
0
–I/O
17
for x18)
SEM
L
SEM
R
Semaphore Enable
UB
L
UB
R
Upper Byte Select (I/O
8
–I/O
15
for x16 devices; I/O
9
–I/O
17
for x18 devices)
LB
L
LB
R
Lower Byte Select (I/O
0
–I/O
7
for x16 devices; I/O
0
–I/O
8
for x18 devices)
INT
L
INT
R
Interrupt Flag
BUSY
L
BUSY
R
Busy Flag
M/S Master or Slave Select
V
CC
Power
GND Ground
NC No Connect
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 5 of 18
generated to the owner. The interrupt is reset when the owner
reads the contents of the mailbox. The message is user defined.
Each port can read the other port’s mailbox without resetting the
interrupt. The active state of the busy signal (to a port) prevents
the port from setting the interrupt to the winning port. Also, an
active busy to a port prevents that port from reading its own
mailbox and, thus, resetting th e interrupt to it.
If an application does not require message passing, do not
connect the interrupt pin to the processor’s interrupt request
input pin.
The operation of the interrupts and their interaction with Busy are
summarized in Table 2.
Busy
The CY7C027V/027VN/027AV/028V and
CY7037V/037AV/038V provide on-chip arbitration to resolve
simultaneous memory location access (contention). If both ports’
CEs are asserted and an address match occurs within t
PS
of each other,
the busy logic determines which port has access. If t
PS
is violated, one
port definitely gains permission to the location, but it is not predictable
which port gets that permission. BUSY is asserted t
BLA
after an address
match or t
BLC
after CE is t aken LOW .
Master/Slave
A M/S pin is provided to expand the word width by configuring the
device as ei ther a master or a sl ave. The BUSY output o f the master is
connected to the BUSY input of the slave. This allows the device to
interface to a master device with no external components. Writing to
slave devices must be delayed until after the BUSY input has settled
(t
BLC
or t
BLA
), otherwise, the slave chip may begin a write cycle during
a contention situat ion. W hen ti ed H IGH, th e 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 CY7C027V/027VN/027AV/028V and
CY7037V/037AV/038V provide eight semaphore latches, which
are separate from the dual-port memory locations. Semaphores
are used to reserve resou rces that are shared betwe en th e 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 zero 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 t
SOP
before attempting to read the semaphore. The
semaphore val ue is available t
SWRD
+ t
DOE
after the risi ng edge of the
semaphore write. If the left port was successful (reads a zero), it
assumes control of the shared resource, otherwise (reads a one) 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 one), the left side succeeds in gaining control of the
semaphore. If the lef t side n o longer requ ires the semapho re, a one is
written to cancel its request.
Semaphores are accessed by asserti ng SEM LOW . The SEM pin
functions as a chip select for the semaphore latche s (C E must remain
HIGH during SEM LOW). A
0–2
represents the semaphore address. OE
and R/W are used in the same manner as a normal memory acces s.
When writing or reading a semaphore, the other address pins have no
effect.
When writing to the semaphore, only I/O
0
is used. If a zero is written
to the left port of an available semaphore, a one appears at the same
semaphore address on the right port. That semaphore can now only be
modified by the side showing zero (the left port in this case). If the left
port now relinquishes control by writing a one to the semaphore, the
semaphore is set to one for both sides. However, if the right port had
requested the semaphore (written a zero) while the left port had control,
the right port would immediately own the semaphore as soon as the left
port released it. Table 3 shows sample semaphore operations.
When reading a semaphore, all sixteen/eighteen 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 t
SPS
of each other , the semaphore is definitely
obtained by one side or the other, but there is no guarantee which side
controls the semaphore .
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 6 of 18
Maximum Ratings
Exceeding maximum ratings may shorten the useful life of the
device. User gui delines are not teste d.
Storage Temperature ............. ... .................–65
°
C to +150
°
C
Ambient Temperature with
Power Applied ............ ................. ... ............–55
°
C to +125
°
C
Supply Voltage to Ground Potential................–0.5V to +4.6V
DC Voltage Applied to
Outputs in High-Z State............. ..............–0.5V to V
CC
+0.5V
DC Input Voltage
[2]
..................................–0.5V to V
CC
+0.5V
Output Current into Outputs (LOW).............................20 mA
Static Discharge Voltage................................... ... .... > 1100V
Latch-up Current................ .................................. .. > 200 mA
Operating Range
Range Ambient
Temperature V
CC
Commercial 0
°
C to +70
°
C 3.3V ± 300 mV
Industrial
[3]
–40
°
C to +85
°
C 3.3V ± 300 mV
Electrical Characteristics
Over the Operating Range
Parameter Description CY7C027V/027VN/027AV/028V/CY7C037V/037AV/038V Unit-15 -20 -25
Min Typ Max Min Typ Max Min Typ Max
V
OH
Output HIGH Voltage
(V
CC
=Min., I
OH
= –4.0 mA) 2.4 2.4 2.4 V
V
OL
Output LOW V oltage (V
CC
=Min., I
OH
= +4.0 mA) 0.4 0.4 0.4 V
V
IH
Input HIGH Voltage 2.2 2.2 2.2 V
V
IL
Input LOW Vol tage 0.8 0.8 0.8 V
I
IX
Input Leakage Current −55−55−55μA
I
OZ
Output Leakage Current –10 10 –10 10 –10 10 μA
I
CC
Operating Current (V
CC
=Max. I
OUT
=0
mA) Outp uts Disabled Com’l. 125 185 120 175 115 165 mA
Ind.
[3]
140 195 mA
I
SB1
Standby Current (Both Ports TTL
Level) CE
L
& CE
R
≥ V
IH
, f=f
MAX
Com’l. 35 50 35 45 30 40 mA
Ind.
[3]
45 55 mA
I
SB2
S t andby Current (One Port TTL Level)
CE
L
| CE
R
≥ V
IH
, f=f
MAX
Com’l. 80 120 75 110 65 95 mA
Ind.
[3]
85 120 mA
I
SB3
Standby Current (Both Ports CMOS
Level) CE
L
& CE
R
≥ V
CC
−0.2V, f=0 Com’l. 10 250 10 250 10 250 μA
Ind.
[3]
10 250 μA
I
SB4
S tandby Current (One Port CMOS Lev-
el) CE
L
| CE
R
≥ V
IH
, f=f
MAX[4]
Com’l. 75 105 70 95 60 80 mA
Ind.
[3]
80 105 mA
Capacitance
[5]
Parameter Description Test Conditions Max Unit
C
IN
Input Capacitance T
A
= 25
°
C, f = 1 MHz,
V
CC
= 3.3V 10 pF
C
OUT
Output Capacitance 10 pF
Notes
2. Puls e w idth < 20 ns .
3. Industrial parts are available in CY7C028V and CY7C038V only.
4. f
MAX
= 1/t
RC
= All inputs cycling at f = 1/t
RC
(except output enable). f = 0 means no address or contro l lines change. Thi s applies only to in puts at CMOS leve l standby I
SB3
.
5. Tested initially and after any design or process changes that may affect these p arameters.
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 7 of 18
Figure 3. AC Test Loads and Waveforms
3.0V
GND 90% 90%
10%
3ns 3ns
10%
ALL INPUTPULSES
(a) Normal Load (Load 1)
R1 = 590Ω
3.3V
OUTPUT
R2 = 435Ω
C= 30pF
V
TH
=1.4V
OUTPUT
C= 30 pF
(b) Thévenin Equivalent (Load 1) (c)Three-State Delay(Load 2)
R1 = 590Ω
R2 = 435Ω
3.3V
OUTPUT
C= 5pF
R
TH
= 250Ω
≤≤
including scope and jig)
(Used for t
LZ
, t
HZ
, t
HZWE
, & t
LZWE
Switching Characteristics
Over the Operating Range
[6]
Parameter Description
CY7C027V/027VN/027AV/028V/
CY7C037V/037AV/038V Unit
-15 -20 -25
Min Max Min Max Min Max
Read Cycle
t
RC
Read Cycle Time 15 20 25 ns
t
AA
Address to Data Valid 15 20 25 ns
t
OHA
Output Hold From Address Change 3 3 3 ns
t
ACE[7]
CE LOW to Data Valid 15 20 25 ns
t
DOE
OE LOW to Data Valid 10 12 13 ns
t
LZOE[8, 9, 10]
OE LOW to Low Z 3 3 3 ns
t
HZOE[8, 9, 10]
OE HIGH to High Z 10 12 15 ns
t
LZCE[8, 9, 10]
CE LOW to Low Z 3 3 3 ns
t
HZCE[8, 9, 10]
CE HIGH to High Z 10 12 15 ns
t
PU[10]
CE LOW to Power Up 0 0 0 ns
t
PD[10]
CE HIGH to Power Down 15 20 25 ns
t
ABE[7]
Byte Enable Access T i me 15 20 25 ns
Write Cycle
t
WC
Write Cycle Time 15 20 25 ns
t
SCE[7]
CE LOW to Write End 12 16 20 ns
t
AW
Address Valid to Write End 12 16 20 ns
t
HA
Address Hold From Write End 0 0 0 ns
t
SA[7]
Address Setup to Write Start 0 0 0 ns
t
PWE
Wr it e Pulse Width 12 17 22 ns
t
SD
Data Setup to Write End 10 12 15 ns
Notes
6. Test conditions assume signal transition t ime of 3 ns or less, ti ming reference levels of 1.5V, input pulse levels of 0 to 3.0V, and o utput loading of the specif ied I
OI
/I
OH
and 30 pF load cap acitance.
7. To access RAM, CE=L, UB=L, SEM=H. To access semaphore, CE=H and SEM=L. Either condition must be valid for the entire t
SCE
time.
8. At any given temperature and voltage condition for any given device, t
HZCE
is less than t
LZCE
and t
HZOE
is less than t
LZOE
.
9. Test conditions used are Load 2.
10.This parameter is guaranteed by design, but it is not production tested. For information on port-to-port delay through RAM cells from writing port to reading port,
refer to Figure 11.
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 8 of 18
Data Retention Mode
The CY7C027V/027VN/027AV/028V and
CY7037V/037AV/038V are designed with battery backup in
mind. Data retention voltage and supply current are guaranteed
over temperature. The following rules ensure data retention:
1. Chip enable (CE) must be held HIGH during data retention, within
V
CC
to V
CC
– 0.2V.
2. CE must be kept between V
CC
– 0.2V and 70% of V
CC
during
the power up and power down transitions.
3. The RAM can begin ope ration >t
RC
after V
CC
reaches the mini-
mum operating vo ltage (3.0 volt s).
t
HD
Data Hold From Write End 0 0 0 ns
t
HZWE[9, 10]
R/W LOW to High Z 10 12 15 ns
t
LZWE[9 ,10]
R/W HIGH to Low Z 3 3 3 ns
t
WDD[36]
Write Pulse to Data Delay 30 40 50 ns
t
DDD[36]
Write Data Valid to Read Data Valid 25 30 35 ns
Busy Timing
[11]
t
BLA
BUSY LOW from Address Match 15 20 20 ns
t
BHA
BUSY HIGH from Address Mismatch 15 20 20 ns
t
BLC
BUSY LOW from CE LOW 15 20 20 ns
t
BHC
BUSY HIGH from CE HIGH 15 16 17 ns
t
PS
Port Setup for Priority 5 5 5 ns
t
WB
R/W HIGH after BUSY (Slave) 0 0 0 ns
t
WH
R/W HIGH after BUSY H I G H ( S l a v e ) 13 15 17 ns
t
BDD[13]
BUSY HIGH to Data Valid 15 20 25 ns
Interrupt Timing
[11]
t
INS
INT Set Time 15 20 20 ns
t
INR
INT Reset Time 15 20 20 ns
Semaphore Timing
t
SOP
SEM Flag Update Pulse (OE or SEM)101012ns
t
SWRD
SEM Flag Write to Read Time 5 5 5 ns
t
SPS
SEM Flag Contention Windo w 5 5 5 ns
t
SAA
SEM Address Access Time 15 20 25 ns
Switching Characteristics
Over the Operating Range
[6]
(continued)
Parameter Description
CY7C027V/027VN/027AV/028V/
CY7C037V/037AV/038V Unit
-15 -20 -25
Min Max Min Max Min Max
Timing
Parameter Test Conditions
[14]
Max Unit
ICC
DR1
At VCC
DR
= 2V 50 μA
Data Retention Mode
3.0V 3.0V
V
CC
> 2.0V
V
CC
to V
CC
–0.2V
V
CC
CE
t
RC
VIH
Notes
11. For information on port-to-port delay through RAM cells f r om writing port to reading port, refer to Figure 11 wavefor m.
12.Test conditions used are Load 1.
13.t
BDD
is a calcul ated param eter and is th e greater of t
WDD
–t
PWE
(actual) or t
DDD
–t
SD
(actual).
14.CE = V
CC
, V
in
= GND to V
CC
, T
A
= 25° C. This parameter is guaranteed but not tested.
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CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 9 of 18
Switching Waveforms
Notes
15.R/W is HIGH for read cycles.
16.Device is continuously selected CE = V
IL
and UB or LB = V
IL
. This waveform cann ot be used for semaph ore reads.
17.OE = V
IL
.
18.Address valid prior to or coincident with CE transition LOW .
19.To access RAM, CE = V
IL
, UB or LB = V
IL
, SEM = V
IH
. To access semaphore, CE = V
IH
, SEM = V
IL
.
t
RC
t
AA
t
OHA
DATA VALIDPREVIOUS DATA VALID
DATA OUT
ADDRESS
t
OHA
Figure 4. Read Cycle No. 1 (Either Port Address Access)
[15, 16, 17]
t
ACE
t
LZOE
t
DOE
t
HZOE
t
HZCE
DATA VALID
t
LZCE
t
PU
t
PD
I
SB
I
CC
DATA OUT
OE
CE and
LB or UB
CURRENT
Figure 5. Read Cycle No. 2 (Either Port CE/OE Access)
[15, 18, 19]
UB or LB
DATAOUT
t
RC
ADDRESS
t
AA
t
OHA
CE
t
LZCE
t
ABE
t
HZCE
t
HZCE
t
ACE
t
LZCE
Figure 6. Read Cycle No. 3 (Either Port)
[15, 17, 18, 19]
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 10 of 18
Notes
20.R/W mu st be HIGH during al l address transitio ns.
21.A write occurs during the overlap (t
SCE
or t
PWE
) of a LOW CE or SEM and a LOW UB or LB.
22.t
HA
is measured from t he earlier of CE or R/W or (SEM or R/W) going HIGH at the end of write cycle.
23.If OE is LOW during a R/W controlled write cycle, the write pulse width must be the larger of t
PWE
or (t
HZWE
+ t
SD
) to allow the I/O drivers to turn off and data to be placed on
the bus for the required t
SD
. If OE is HIGH during an R/W controlled write cycle, this requirement does not apply and the write pulse can be as short as the specified t
PWE
.
24.To access RAM, CE = V
IL
, SEM = V
IH
.
25.To access upper byte, CE = V
IL
, UB = V
IL
, SEM = V
IH
.
To access low er byte, CE = V
IL
, LB = V
IL
, SEM = V
IH
.
26.Transition is measured ±500 mV from steady st ate with a 5 pF load (includi ng scope and jig) . This para meter is sampled a nd not 100% teste d.
27.During this period, the I/O pins are in the output state, and input signals must not be applied.
28.If the CE or SEM LOW transition occurs simultaneously with or after the R/W LOW transition, the outputs remain in the high impedance state.
Switching Waveforms
(continued)
t
AW
t
WC
t
PWE
t
HD
t
SD
t
HA
CE
R/W
OE
DATAOUT
DATA IN
ADDRESS
t
HZOE
t
SA
t
HZWE
t
LZWE
Figure 7. Write Cycle No. 1: R/W Controlled Timing
[20, 21, 22, 23]
[26]
[26]
[23]
[24,25]
NOTE 27 NOTE 27
t
AW
t
WC
t
SCE
t
HD
t
SD
t
HA
CE
R/W
DATA IN
ADDRESS
t
SA
Figure 8. Write Cycle No. 2: CE Controlled Timing
[20, 21, 22, 28]
[24,25]
[+] Feedback
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 11 of 18
Notes
29.CE = HIGH for the duration of the above timing (both write and read cycle).
30.I/O
0R
= I/O
0L
= LOW (request semaphore); CE
R
= CE
L
= HIGH.
31.Semaphores are reset (available to both ports) at cycle start.
32.If t
SPS
is violated, the semaphore is def initely obt ained by one side or the other , but which side get s the semaphor e is unpredict able.
Switching Waveforms
(continued)
t
SOP
t
SAA
VALID ADRESS VALID ADRESS
t
HD
DATA
IN
VALID DATA
OUT
VALID
t
OHA
t
AW
t
HA
t
ACE
t
SOP
t
SCE
t
SD
t
SA
t
PWE
t
SWRD
t
DOE
WRITE CYCLE READ CYCLE
OE
R/W
I/O
0
SEM
0
–A
2
Figure 9. Semaphore Read After Write Timing, Either Side
[29]
A
MATCH
t
SPS
A
0L
–A
2L
MATCH
R/W
L
SEM
L
A
0R
–A
2R
R/W
R
SEM
R
Figure 10. Timing Diagram of Semaphore Contention
[30, 31, 32]
[+] Feedback
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CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 12 of 18
Note
33.CE
L
= CE
R
= LOW.
Switching Waveforms
(continued)
VALID
t
DDD
t
WDD
MATCH
MATCH
R/W
R
DATA IN
R
DATA
OUTL
t
WC
ADDRESS
R
t
PWE
VALID
t
SD
t
HD
ADDRESS
L
t
PS
t
BLA
t
BHA
t
BDD
BUSY
L
Figure 11. Timing Diagram of Read with BUSY (M/S=HIGH)
[33]
t
PWE
R/W
BUSY t
WB
t
WH
Figure 12. Write Timing with Busy Input (M/S=LOW)
[+] Feedback
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Document #: 38-06078 Rev. *B Page 13 of 18
Note
34.If t
PS
is violated, th e busy signal is asse rted on one side o r the other , but there is no g uarantee to which si de BUSY is asserted.
Switching Waveforms
(continued)
ADDRESS MATCH
t
PS
t
BLC
t
BHC
ADDRESS MATCH
t
PS
t
BLC
t
BHC
CE
R
ValidFirst:
ADDRESS
L,R
BUSY
R
CE
L
CE
R
BUSY
L
CE
R
CE
L
ADDRESS
L,R
Figure 13. Busy Timing Diagram No. 1 (CE Arbitration)
[34]
CE
L
Valid First:
ADDRESS MATCH
t
PS
ADDRESS
L
BUSY
R
ADDRESS MISMATCH
t
RC
or t
WC
t
BLA
t
BHA
ADDRESS
R
ADDRESS MATCH ADDRESS MISMATCH
t
PS
ADDRESS
L
BUSY
L
t
RC
or t
WC
t
BLA
t
BHA
ADDRESS
R
Right AddressValid First:
Figure 14. Busy Timing Diagram No. 2 (Address Arb itr ation)
[34]
Left Address Valid First:
[+] Feedback
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CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 14 of 18
Figure 15. Interrupt Timing Diagrams
Notes
35.t
HA
depends on whi ch enable pi n (CE
L
or R/W
L
) is deasserted first.
36.t
INS
or t
INR
depends on which en able pin (CE
L
or R/W
L
) is asserted last.
Switching Waveforms
(continued)
WRITE 7FFF (FFFF for CY7 C028V/38V)
t
WC
Right SideClears INT
R
:
t
HA
READ 7FFF
t
RC
t
INR
WRITE 7FFE (FFFE for CY7C028V/38V)
t
WC
Right SideSets INT
L
:
Left Side Sets INT
R
:
Left SideClears INT
L
:
READ 7FFE
t
INR
t
RC
ADDRESS
R
CE
L
R/W
L
INT
L
OE
L
ADDRESS
R
R/W
R
CE
R
INT
L
ADDRESS
R
CE
R
R/W
R
INT
R
OE
R
ADDRESS
L
R/W
L
CE
L
INT
R
t
INS
t
HA
t
INS
(FFFF for CY7C028V/38V)
(FFFF for CY7C028V/38V)
[35]
[36]
[36]
[36]
[35]
[36]
[+] Feedback
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CY7C037V/037AV/038V
Document #: 38-06078 Rev. *B Page 15 of 18
Table 1. Non-Contending Read/Write
Inputs Outputs
CE R/W OE UB LB SEM I/O
9
–I/O
17
I/O
0
–I/O
8
Operation
H X X X X H High Z High Z Deselected: Power Down
X X X H H H High Z High Z Deselected: Power Down
L L X L H H Data In High Z Write to Upper Byte Only
L L X H L H High Z Data In Write to Lower Byte Only
L L X L L H Data In Data In Write to Both Bytes
L H L L H H Data Out High Z Read Upper Byte Only
L H L H L H High Z Data Out Read Lower Byte Only
L H L L L H Data Out Data Out Read Both Bytes
X X H X X X High Z High Z Outputs Disabled
H H L X X L Data Out Data Out Read Data in Semaphore Flag
X H L H H L Data Out Data Out Read Data in Semaphore Flag
H X X X L Data In Data In Write D
IN0
into Semaphore Flag
X X H H L Data In Data In Write D
IN0
into Semaphore Flag
L X X L X L Not Allowed
L X X X L L Not Allowed
Table 2. Interrupt Operation Example (assumes BUSY
L
=BUSY
R
=HIGH)
[37]
Left Port Right Port
Function R/W
L
CE
L
OE
L
A
0L–14L
INT
L
R/W
R
CE
R
OE
R
A
0R–14R
INT
R
Set Right INT
R
Flag L L X 7FFF X X X X X L
[39]
Reset Right INT
R
FlagXXXXXXLL7FFFH
[38]
Set Left INT
L
Flag XXX X L
[38]
LLX 7FFE X
Reset Left INT
L
Flag X L L 7FFE H
[39]
XXX X X
Table 3. Semaphore Operation Example
Function I/O
0
–I/O
17
Left I/O
0
–I/O
17
Right Status
No action 1 1 Semaphore free
Left port writes 0 to semaphore 0 1 Left port has semaphore token
Right port writes 0 to semaphore 0 1 No change. Ri ght side has no write access to semaphore
Left port writes 1 to semaphore 1 0 Right port obtains semapho re token
Left port writes 0 to semaphore 1 0 No change. Left port has no write access to semaphore
Right port writes 1 to semaphore 0 1 Left port obtains semaphore token
Left port writes 1 to semaphore 1 1 Semaphore free
Right port writes 0 to semaphore 1 0 Right port has semaphore token
Right port writes 1 to semaphore 1 1 Semaphore free
Left port writes 0 to semaphore 0 1 Left port has semaphore token
Left port writes 1 to semaphore 1 1 Semaphore free
Notes
37.A
0L–15L
and A
0R–15R
,FFFF/FFFE for the CY7C028V/03 8V.
38. If BUSY
R
=L, then no chan ge.
39. If BUSY
L
=L, then no change.
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Document #: 38-06078 Rev. *B Page 16 of 18
Ordering Information
32K x16 3.3V Asynchronous Dual-Port SRAM
Speed
(ns) Orderin g Code Package
Name Package Type Operating
Range
15 CY7C027V-15AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C027V-15 AXC A100 100-Pin Pb-Free Th in Quad Flat Pack Commercial
CY7C027VN-15AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
20 CY7C027V-20AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C027V-20 AXC A100 100-Pin Pb-Free Th in Quad Flat Pack Commercial
25 CY7C027V-25AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C027V-25AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
CY7C027AV-25AXI A100 100-Pin Pb-Free Thin Quad Flat Pack Industrial
64K x16 3.3V Asynchronous Dual-Port SRAM
Speed
(ns) Orderin g Code Package
Name Package Type Operating
Range
15 CY7C028V-15AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C028V-15AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
20 CY7C028V-20AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C028V-20AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
CY7C028V-20AI A100 100-Pin Thin Quad Flat Pack Industrial
CY7C028V-20AXI A100 100-Pin Pb-Free Th in Quad Flat Pack Industrial
25 CY7C028V-25AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C028V-25AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
32K x18 3.3V Asynchronous Dual-Port SRAM
Speed
(ns) Orderin g Code Package
Name Package Type Operating
Range
15 CY7C037V-15AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C037V-15AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
20 CY7C037V-20AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C037AV-20AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
25 CY7C037V-25AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C037V-25AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
64K x18 3.3V Asynchronous Dual-Port SRAM
Speed
(ns) Orderin g Code Package
Name Package Type Operating
Range
15 CY7C038V-15AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C038V-15AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
20 CY7C038V-20AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C038V-20AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
CY7C038V-20AI A100 100-Pin Thin Quad Flat Pack Industrial
CY7C038V-20AXI A100 100-Pin Pb-Free Th in Quad Flat Pack Industrial
25 CY7C038V-25AC A100 100-Pin Thin Quad Flat Pack Commercial
CY7C038V-25AXC A100 100-Pin Pb-Free Thin Quad Flat Pack Commercial
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Document #: 38-06078 Rev. *B Revised December 09, 2008 Page 18 of 18
All products and company names mentioned in this document may be the trademarks o f t heir respect i ve holders.
CY7C027V/027VN/027AV/028V
CY7C037V/037AV/038V
© Cypress Semicondu ctor Corpor ation, 2001-200 8. The informati on cont ained herein is subject to change witho ut notice. Cypr ess 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 pro d ucts ar e not war ran ted no r inte nd ed to be used fo r
medical, life supp or t, l if e savi n g, cr it ical control or safety ap pl ic at ions, unless pursuant to a n express written agre ement with Cypress. Furth erm or e, Cyp ress doe s not auth or iz e its products for use as
critical components in life-support systems where a malfunction or failur e may reasonably be expected to result in significant injury to the user. The inclusion of Cypress product s in life-support syst ems
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 inter nation al trea ty provisi ons. Cyp ress he reby gr ant s t o license e a per sonal , non- exclus ive, no n-tran sferab le lic ense to cop y, use, modify, create derivati ve 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 lice nsee product to be used on ly in conjunction wit h a Cypress
integrated circui t as specified in the applicab le agreement. Any r eproduction, m odification, transl ation, compilatio n, or represent ation of this S ource Code exce pt as specified above is prohib ited 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 MERCHANTAB ILITY 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 liabil ity ar ising ou t of t he app licati on or us e of an y product or circ uit de scrib ed herei n. Cypr ess does n ot auth orize it s product s for use a s critical componen ts in life-suppo rt 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.
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Document Title: CY7C027V/027VN/027AV/CY7C028V/037V/037AV/038V 3.3V 32K/64K x 16/18 Dual Port Static RAM
Document Number: 38-06078
Rev. ECN No. Orig. of
Change Submission
Date Description of Change
** 237626 YDT 6/30/04 Converted data sheet from old spec 38-00670 to conform with new data
sheet. Removed cross information from features section
*A 259110 JHX See ECN Added Pb-Free packaging information.
*B 2623540 VKN/PYRS 12/17/08 Added CY7C027VN, CY7C027AV and CY7C037AV parts
Updated Ordering information table
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