Cypress CY7C027V User Manual

CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
3.3V 32K/64K x 16/18 Dual-Port Static  
RAM  
Fully asynchronous operation  
Automatic power down  
Features  
True Dual-Ported memory cells which allow  
Expandable data bus to 32/36 bits or more using Master/Slave  
chip select when using more than one device  
simultaneous access of the same memory location  
32K x 16 organization (CY7C027V/027VN/027AV [1]  
)
On-chip arbitration logic  
64K x 16 organization (CY7C028V)  
Semaphores included to permit software handshaking  
between ports  
32K x 18 organization (CY7C037V/037AV[2]  
64K x 18 organization (CY7C038V)  
)
INT flag for port-to-port communication  
Separate upper-byte and lower-byte control  
Dual chip enables  
0.35 micron CMOS for optimum speed and power  
High speed access: 15, 20, and 25 ns  
Low operating power  
Pin select for Master or Slave  
Active: ICC = 115 mA (typical)  
Commercial and Industrial temperature ranges  
100-pin Pb-free TQFP and 100-pin TQFP  
Standby: ISB3 = 10 μA (typical)  
Logic Block Diagram  
R/W  
R/W  
UB  
L
R
R
UB  
L
CE  
CE  
CE  
CE  
0L  
1L  
0R  
1R  
CE  
CE  
R
L
LB  
LB  
R
L
L
OE  
OE  
R
8/9  
8/9  
[3]  
15/17L  
[4]  
I/O  
–I/O  
I/O  
–I/O[3]  
8/9L  
8/9L  
15/17R  
[4]  
8/9  
8/9  
I/O  
Control  
I/O  
Control  
I/O –I/O  
I/O –I/O  
0L  
7/8L  
0L  
7/8R  
15/16  
15/16  
[5]  
A
A
–A[5]  
A
A
–A  
Address  
Decode  
Address  
Decode  
True Dual-Ported  
0L  
14/15L  
0R  
14/15R  
14/15R  
RAM Array  
15/16  
15/16  
–A[5]  
[5]  
–A  
0L  
14/15L  
0R  
CE  
CE  
R
Interrupt  
Semaphore  
Arbitration  
L
OE  
OE  
R
L
R/W  
SEM  
R/W  
SEM  
L
R
R
L
[6]  
BUSY  
INT  
BUSY  
INT  
UB  
L
R
R
R
R
L
UB  
L
LB  
M/S  
LB  
L
Notes  
1. CY7C027V, CY7C027VN and CY7C027AV are functionally identical.  
2. CY7C037V and CY7C037AV are functionally identical.  
3. I/O –I/O for x16 devices; I/O –I/O for x18 devices.  
8
15  
9
17  
4. I/O –I/O for x16 devices; I/O –I/O for x18 devices.  
0
7
0
8
5. A –A for 32K; A –A for 64K devices.  
0
14  
0
15  
6. BUSY is an output in master mode and an input in slave mode.  
Cypress Semiconductor Corporation  
Document #: 38-06078 Rev. *B  
198 Champion Court  
San Jose, CA 95134-1709  
408-943-2600  
Revised December 09, 2008  
           
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Pin Configurations (continued)  
Figure 2. 100-Pin TQFP (Top View)  
100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76  
A9L  
A10L  
A11L  
1
2
3
75  
74  
73  
72  
71  
70  
69  
68  
67  
66  
65  
64  
63  
62  
61  
60  
59  
58  
57  
56  
55  
54  
53  
52  
51  
A8R  
A9R  
A10R  
A11R  
A12R  
A13R  
A14R  
A15R  
LBR  
A12L  
A13L  
4
5
A14L  
6
[2] A15L  
LBL  
7
[2]  
8
UBL  
9
CE0L  
CE1L  
SEML  
R/WL  
OEL  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
UBR  
CE0R  
CE1R  
SEMR  
R/WR  
GND  
OER  
GND  
CY7C038V (64K x 18)  
CY7C037V/037AV (32K x 18)  
VCC  
GND  
I/O17L  
I/O16L  
GND  
I/O17R  
GND  
I/O15L  
I/O14L  
I/O13L  
I/O12L  
I/O16R  
I/O15R  
I/O14R  
I/O13R  
I/O12R  
I/O11R  
I/O11L  
I/O10L  
24  
25  
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50  
Selection Guide  
Parameter  
-15  
15  
-20  
20  
-25  
Unit  
ns  
Maximum Access Time  
25  
Typical Operating Current  
125  
35  
120  
35  
115  
30  
mA  
mA  
μA  
Typical Standby Current for ISB1 (Both ports TTL level)  
Typical Standby Current for ISB3 (Both ports CMOS level)  
10 μA  
10 μA  
10 μA  
Note  
2. This pin is NC for CY7C037V/037AV.  
Document #: 38-06078 Rev. *B  
Page 3 of 18  
 
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Pin Definitions  
Left Port  
CE0L, CE1L  
R/WL  
Right Port  
CE0R, CE1R  
Description  
Chip Enable (CE is LOW when CE0 VIL and CE1 VIH)  
R/WR  
Read/Write Enable  
OEL  
OER  
Output Enable  
A
0L–A15L  
A0R–A15R  
I/O0R–I/O17R  
SEMR  
UBR  
Address (A0–A14 for 32K; A0–A15 for 64K devices)  
I/O0L–I/O17L  
SEML  
UBL  
Data Bus Input/Output (I/O0–I/O15 for x16 devices; I/O0–I/O17 for x18)  
Semaphore Enable  
Upper Byte Select (I/O8–I/O15 for x16 devices; I/O9–I/O17 for x18 devices)  
LBL  
LBR  
Lower Byte Select (I/O0–I/O7 for x16 devices; I/O0–I/O8 for x18 devices)  
INTL  
INTR  
Interrupt Flag  
Busy Flag  
BUSYL  
M/S  
BUSYR  
Master or Slave Select  
Power  
VCC  
GND  
NC  
Ground  
No Connect  
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  
Architecture  
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 select (CE) pin.  
The  
CY7C027V/027VN/027AV/028V  
and  
CY7037V/037AV/038V consist of an array of 32K and 64K words  
of 16 and 18 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/reads to the same location, a BUSY 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 data to be read from the device.  
The  
CY7C027V/027VN/027AV/028V  
and  
CY7037V/037AV/038V are available in 100-pin Thin Quad Plas-  
tic Flatpacks (TQFP).  
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 R/W pin (see Figure 7) or the CE pin (see Figure 8). Required inputs  
for non-contention operations are summarized in Table 1.  
Functional Description  
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 data is read on the output; otherwise the  
data read is not deterministic. Data is valid on the port tDDD after  
the data is presented on the other port.  
The  
CY7C027V/027VN/027AV/028V  
and  
CY7037V/037AV/038V are low power CMOS 32K, 64K 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 of 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 logic. Ap-  
plication areas include interprocessor/multiprocessor designs,  
communications status buffering, and dual-port video/graphics  
memory.  
Read Operation  
When reading the device, the user must assert both the OE and  
CE pins. Data is available tACE after CE or tDOE 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/027AV/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 writes to the other port’s mailbox, an interrupt is  
Each port has independent control 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 other port.  
The interrupt flag (INT) permits communication between ports or  
Document #: 38-06078 Rev. *B  
Page 4 of 18  
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
generated to the owner. The interrupt is reset when the owner  
reads the contents of the mailbox. The message is user defined.  
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 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 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 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 left side no longer requires the semaphore, a one is  
written to cancel its request.  
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 the 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  
Semaphores are accessed by asserting SEM LOW. The SEM pin  
functions as a chip select 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.  
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 assertedandanaddress matchoccurs withintPS of eachother,  
the busy logic determines which port has access. If tPS is violated, one  
port definitely gains permission to the location, but it is not predictable  
which port gets that permission. BUSY is asserted tBLA after an address  
match or tBLC after CE is taken LOW.  
When writing to the semaphore, only I/O0 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.  
Master/Slave  
A M/S pin is provided 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 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  
(tBLC or tBLA), otherwise, the slave chip may begin a write cycle during  
a contention situation. When tied HIGH, the M/S pin allows the device  
tobeusedasa master and, therefore, theBUSYline is anoutput. BUSY  
can then be used to send the arbitration outcome to a slave.  
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 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.  
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  
Document #: 38-06078 Rev. *B  
Page 5 of 18  
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
DC Input Voltage[2] .................................. –0.5V to VCC+0.5V  
Output Current into Outputs (LOW)............................. 20 mA  
Static Discharge Voltage.......................................... > 1100V  
Latch-up Current.................................................... > 200 mA  
Maximum Ratings  
Exceeding maximum ratings may shorten the useful life of the  
device. User guidelines are not tested.  
Storage Temperature .................................65°C to +150°C  
Ambient Temperature with  
Power Applied ............................................55°C to +125°C  
Operating Range  
Ambient  
Supply Voltage to Ground Potential................–0.5V to +4.6V  
Range  
Commercial  
Industrial[3]  
Temperature  
0°C to +70°C  
–40°C to +85°C  
VCC  
DC Voltage Applied to  
Outputs in High-Z State ...........................0.5V to VCC+0.5V  
3.3V ± 300 mV  
3.3V ± 300 mV  
Electrical Characteristics Over the Operating Range  
CY7C027V/027VN/027AV/028V/CY7C037V/037AV/038V  
-15 -20 -25  
Min Typ Max Min Typ Max Min Typ Max  
Parameter  
Description  
Unit  
VOH  
Output HIGH Voltage  
(VCC=Min., IOH= –4.0 mA)  
2.4  
2.4  
2.4  
V
VOL  
VIH  
VIL  
IIX  
Output LOW Voltage (VCC=Min., IOH= +4.0 mA)  
Input HIGH Voltage  
0.4  
0.4  
0.4  
V
2.2  
2.2  
2.2  
V
Input LOW Voltage  
0.8  
5
0.8  
5
0.8  
V
Input Leakage Current  
5  
5  
5  
5
10  
μA  
μA  
mA  
mA  
mA  
mA  
mA  
mA  
μA  
μA  
mA  
mA  
IOZ  
ICC  
Output Leakage Current  
–10  
10 –10  
125 185  
10  
–10  
Operating Current (VCC=Max. IOUT=0 Com’l.  
mA) Outputs Disabled  
Ind.[3]  
120 175  
140 195  
115 165  
ISB1  
ISB2  
ISB3  
ISB4  
Standby Current (Both Ports TTL  
Level) CEL & CER VIH, f=fMAX  
Com’l.  
Ind.[3]  
35  
50  
35  
45  
75  
85  
10  
10  
70  
80  
45  
55  
30  
65  
10  
60  
40  
95  
Standby Current (One Port TTL Level) Com’l.  
80 120  
10 250  
75 105  
110  
120  
250  
250  
95  
CEL | CER VIH, f=fMAX  
Ind.[3]  
Com’l.  
Ind.[3]  
Standby Current (Both Ports CMOS  
Level) CEL & CER VCC0.2V, f=0  
250  
80  
Standby Current (One Port CMOS Lev- Com’l.  
[4]  
el) CEL | CER VIH, f=fMAX  
Ind.[3]  
105  
Capacitance[5]  
Parameter  
Description  
Input Capacitance  
Output Capacitance  
Test Conditions  
Max  
Unit  
CIN  
TA = 25°C, f = 1 MHz,  
CC = 3.3V  
10  
10  
pF  
pF  
V
COUT  
Notes  
2. Pulse width < 20 ns.  
3. Industrial parts are available in CY7C028V and CY7C038V only.  
4.  
f
= 1/t = All inputs cycling at f = 1/t (except output enable). f = 0 means no address or control lines change. This applies only to inputs at CMOS level standby I  
.
MAX  
RC  
RC  
SB3  
5. Tested initially and after any design or process changes that may affect these parameters.  
Document #: 38-06078 Rev. *B  
Page 6 of 18  
       
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Figure 3. AC Test Loads and Waveforms  
3.3V  
3.3V  
R
TH  
= 250Ω  
R1 = 590Ω  
OUTPUT  
C = 30 pF  
OUTPUT  
C = 30 pF  
R1 = 590Ω  
OUTPUT  
C = 5 pF  
R2 = 435Ω  
R2 = 435Ω  
V
TH  
= 1.4V  
(a) Normal Load (Load 1)  
(c) Three-State Delay(Load 2)  
(b) Thévenin Equivalent (Load 1)  
(Used for tLZ, tHZ, tHZWE, & tLZWE  
including scope and jig)  
ALL INPUTPULSES  
3.0V  
GND  
90%  
90%  
10%  
3 ns  
10%  
3 ns  
Switching Characteristics Over the Operating Range[6]  
CY7C027V/027VN/027AV/028V/  
CY7C037V/037AV/038V  
Parameter  
Description  
Unit  
-15  
-20  
-25  
Min  
15  
3
Max  
Min  
20  
3
Max  
Min  
25  
3
Max  
Read Cycle  
tRC  
Read Cycle Time  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
tAA  
Address to Data Valid  
Output Hold From Address Change  
CE LOW to Data Valid  
OE LOW to Data Valid  
OE LOW to Low Z  
15  
20  
25  
tOHA  
tACE  
tDOE  
tLZOE  
15  
10  
20  
12  
25  
13  
3
3
0
3
3
0
3
3
0
tHZOE  
OE HIGH to High Z  
10  
10  
12  
12  
15  
15  
tLZCE  
CE LOW to Low Z  
tHZCE  
CE HIGH to High Z  
tPU  
tPD  
CE LOW to Power Up  
CE HIGH to Power Down  
Byte Enable Access Time  
15  
15  
20  
20  
25  
25  
tABE  
Write Cycle  
tWC  
Write Cycle Time  
15  
12  
12  
0
20  
16  
16  
0
25  
20  
20  
0
ns  
ns  
ns  
ns  
ns  
ns  
ns  
tSCE  
CE LOW to Write End  
Address Valid to Write End  
Address Hold From Write End  
Address Setup to Write Start  
Write Pulse Width  
tAW  
tHA  
[7]  
tSA  
0
0
0
tPWE  
12  
10  
17  
12  
22  
15  
tSD  
Data Setup to Write End  
Notes  
6. 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 I /I  
OI OH  
and 30 pF load capacitance.  
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  
time.  
SCE  
8. At any given temperature and voltage condition for any given device, t  
9. Test conditions used are Load 2.  
is less than t  
and t  
is less than t  
.
HZCE  
LZCE  
HZOE  
LZOE  
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.  
Document #: 38-06078 Rev. *B  
Page 7 of 18  
         
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Switching Characteristics Over the Operating Range[6](continued)  
CY7C027V/027VN/027AV/028V/  
CY7C037V/037AV/038V  
Unit  
Parameter  
Description  
-15  
-20  
-25  
Min  
Max  
Min  
Max  
Min  
Max  
tHD  
tHZWE  
Data Hold From Write End  
R/W LOW to High Z  
0
0
0
ns  
ns  
ns  
ns  
ns  
10  
12  
15  
tLZWE  
R/W HIGH to Low Z  
3
3
3
tWDD  
Write Pulse to Data Delay  
Write Data Valid to Read Data Valid  
30  
25  
40  
30  
50  
35  
tDDD  
Busy Timing[11]  
tBLA  
BUSY LOW from Address Match  
BUSY HIGH from Address Mismatch  
BUSY LOW from CE LOW  
BUSY HIGH from CE HIGH  
Port Setup for Priority  
15  
15  
15  
15  
20  
20  
20  
16  
20  
20  
20  
17  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
tBHA  
tBLC  
tBHC  
tPS  
5
0
5
0
5
0
tWB  
R/W HIGH after BUSY (Slave)  
R/W HIGH after BUSY HIGH (Slave)  
BUSY HIGH to Data Valid  
tWH  
13  
15  
17  
[13]  
tBDD  
Interrupt Timing[11]  
15  
20  
25  
tINS  
INT Set Time  
15  
15  
20  
20  
20  
20  
ns  
ns  
tINR  
INT Reset Time  
Semaphore Timing  
tSOP  
tSWRD  
tSPS  
SEM Flag Update Pulse (OE or SEM)  
SEM Flag Write to Read Time  
SEM Flag Contention Window  
SEM Address Access Time  
10  
5
10  
5
12  
5
ns  
ns  
ns  
ns  
5
5
5
tSAA  
15  
20  
25  
Data Retention Mode  
Timing  
The  
CY7C027V/027VN/027AV/028V  
and  
Data Retention Mode  
3.0V  
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:  
V
CC  
3.0V  
V
CC  
> 2.0V  
t
RC  
1. Chip enable (CE) must be held HIGH during data retention, within  
VCC to VCC – 0.2V.  
V
CC  
to V – 0.2V  
CC  
V
IH  
CE  
2. CE must be kept between VCC – 0.2V and 70% of VCC during  
the power up and power down transitions.  
3. The RAM can begin operation >tRC after VCC reaches the mini-  
mum operating voltage (3.0 volts).  
Parameter  
ICCDR1  
Test Conditions[14]  
Max  
50  
Unit  
At VCCDR = 2V  
μA  
Notes  
11. For information on port-to-port delay through RAM cells from writing port to reading port, refer to Figure 11 waveform.  
12. Test conditions used are Load 1.  
13. t  
is a calculated parameter and is the greater of t  
–t  
(actual) or t  
–t (actual).  
BDD  
WDD PWE  
DDD SD  
14. CE = V , V = GND to V , T = 25° C. This parameter is guaranteed but not tested.  
CC  
in  
CC  
A
Document #: 38-06078 Rev. *B  
Page 8 of 18  
     
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Switching Waveforms  
Figure 4. Read Cycle No. 1 (Either Port Address Access)[15, 16, 17]  
t
RC  
ADDRESS  
DATA OUT  
t
AA  
t
t
OHA  
OHA  
PREVIOUS DATAVALID  
DATA VALID  
Figure 5. Read Cycle No. 2 (Either Port CE/OE Access)[15, 18, 19]  
t
ACE  
CE and  
LB or UB  
t
HZCE  
t
DOE  
OE  
t
HZOE  
t
LZOE  
DATA VALID  
DATA OUT  
t
LZCE  
t
PU  
t
PD  
I
CC  
CURRENT  
I
SB  
Figure 6. Read Cycle No. 3 (Either Port)[15, 17, 18, 19]  
t
RC  
ADDRESS  
UB or LB  
t
AA  
t
OHA  
t
t
HZCE  
t
t
LZCE  
LZCE  
t
ABE  
CE  
HZCE  
t
ACE  
DATA OUT  
Notes  
15. R/W is HIGH for read cycles.  
16. Device is continuously selected CE = V and UB or LB = V . This waveform cannot be used for semaphore reads.  
IL  
IL  
17. OE = V .  
IL  
18. Address valid prior to or coincident with CE transition LOW.  
19. To access RAM, CE = V , UB or LB = V , SEM = V . To access semaphore, CE = V , SEM = V .  
IL  
IL  
IH  
IH  
IL  
Document #: 38-06078 Rev. *B  
Page 9 of 18  
         
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Switching Waveforms(continued)  
Figure 7. Write Cycle No. 1: R/W Controlled Timing[20, 21, 22, 23]  
t
WC  
ADDRESS  
OE  
t
HZOE  
t
AW  
[24,25]  
CE  
PWE  
t
t
t
HA  
SA  
R/W  
DATAOUT  
DATA IN  
HZWE  
t
t
LZWE  
t
t
HD  
SD  
Figure 8. Write Cycle No. 2: CE Controlled Timing[20, 21, 22, 28]  
t
WC  
ADDRESS  
t
AW  
[24,25]  
CE  
t
t
t
HA  
SA  
SCE  
R/W  
t
t
HD  
SD  
DATA IN  
Notes  
20. R/W must be HIGH during all address transitions.  
21. A write occurs during the overlap (t  
or t  
) of a LOW CE or SEM and a LOW UB or LB.  
SCE  
PWE  
22. t is measured from the earlier of CE or R/W or (SEM or R/W) going HIGH at the end of write cycle.  
HA  
23. If OE is LOW during a R/W controlled write cycle, the write pulse width must be the larger of t  
or (t  
+ t ) to allow the I/O drivers to turn off and data to be placed on  
PWE  
HZWE SD  
the bus for the required t . 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  
.
SD  
PWE  
24. To access RAM, CE = V , SEM = V  
.
IL  
IH  
25. To access upper byte, CE = V , UB = V , SEM = V .  
IL  
IL  
IH  
To access lower byte, CE = V , LB = V , SEM = V .  
IL  
IL  
IH  
26. Transition is measured ±500 mV from steady state with a 5 pF load (including scope and jig). This parameter is sampled and not 100% tested.  
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.  
Document #: 38-06078 Rev. *B  
Page 10 of 18  
                     
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Switching Waveforms(continued)  
Figure 9. Semaphore Read After Write Timing, Either Side[29]  
t
t
OHA  
SAA  
A0–A  
VALID ADRESS  
VALID ADRESS  
2
t
AW  
t
ACE  
t
HA  
SEM  
t
t
SOP  
SCE  
t
SD  
I/O  
0
DATA VALID  
DATA  
VALID  
IN  
OUT  
t
HD  
t
t
PWE  
SA  
R/W  
OE  
t
t
DOE  
SWRD  
t
SOP  
WRITE CYCLE  
READ CYCLE  
Figure 10. Timing Diagram of Semaphore Contention[30, 31, 32]  
A
0L  
–A  
2L  
MATCH  
R/W  
L
SEM  
–A  
L
t
SPS  
A
MATCH  
0R  
2R  
R/W  
R
SEM  
R
Notes  
29. CE = HIGH for the duration of the above timing (both write and read cycle).  
30. I/O = I/O = LOW (request semaphore); CE = CE = HIGH.  
0R  
0L  
R
L
31. Semaphores are reset (available to both ports) at cycle start.  
32. If t is violated, the semaphore is definitely obtained by one side or the other, but which side gets the semaphore is unpredictable.  
SPS  
Document #: 38-06078 Rev. *B  
Page 11 of 18  
       
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Switching Waveforms(continued)  
Figure 11. Timing Diagram of Read with BUSY (M/S=HIGH)[33]  
t
WC  
ADDRESS  
R
MATCH  
t
PWE  
R/W  
R
t
t
HD  
SD  
DATA IN  
VALID  
R
t
PS  
ADDRESS  
L
MATCH  
t
BLA  
t
BHA  
BUSY  
L
t
BDD  
t
DDD  
DATA  
VALID  
OUTL  
t
WDD  
Figure 12. Write Timing with Busy Input (M/S=LOW)  
t
PWE  
R/W  
t
t
WH  
WB  
BUSY  
Note  
33. CE = CE = LOW.  
L
R
Document #: 38-06078 Rev. *B  
Page 12 of 18  
   
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Switching Waveforms(continued)  
Figure 13. Busy Timing Diagram No. 1 (CE Arbitration)[34]  
CELValid First:  
ADDRESS  
L,R  
ADDRESS MATCH  
CE  
L
t
PS  
CE  
R
t
t
BHC  
BLC  
BUSY  
R
CER ValidFirst:  
ADDRESS  
L,R  
ADDRESS MATCH  
CE  
R
t
PS  
CE  
L
L
t
t
BHC  
BLC  
BUSY  
Figure 14. Busy Timing Diagram No. 2 (Address Arbitration)[34]  
Left Address Valid First:  
t
or t  
WC  
RC  
ADDRESS  
L
ADDRESS MATCH  
ADDRESS MISMATCH  
t
PS  
ADDRESS  
R
t
t
BHA  
BLA  
BUSY  
R
Right AddressValid First:  
t
or t  
WC  
RC  
ADDRESS  
R
ADDRESS MATCH  
ADDRESS MISMATCH  
t
PS  
ADDRESS  
L
t
t
BHA  
BLA  
BUSY  
L
Note  
34. If t is violated, the busy signal is asserted on one side or the other, but there is no guarantee to which side BUSY is asserted.  
PS  
Document #: 38-06078 Rev. *B  
Page 13 of 18  
 
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Switching Waveforms(continued)  
Figure 15. Interrupt Timing Diagrams  
Left Side Sets INT :  
R
t
WC  
ADDRESS  
L
WRITE 7FFF (FFFF for CY7C028V/38V)  
[35]  
t
HA  
CE  
L
R/W  
INT  
L
R
t
INS  
Right Side Clears INT :  
R
t
RC  
READ 7FFF  
(FFFF for CY7C028V/38V)  
ADDRESS  
R
CE  
R
t
INR  
R/W  
R
OE  
R
INT  
R
:
Right Side Sets INTL  
t
WC  
ADDRESS  
R
WRITE 7FFE (FFFE for CY7C028V/38V)  
[35]  
t
HA  
CE  
R
R
R/W  
INT  
L
INS  
t
Left SideClears INT :  
L
t
RC  
READ 7FFE  
(FFFF for CY7C028V/38V)  
ADDRESS  
CE  
R
L
t
INR  
R/W  
OE  
L
L
L
INT  
Notes  
35. t depends on which enable pin (CE or R/W ) is deasserted first.  
HA  
L
L
36. t or t depends on which enable pin (CE or R/W ) is asserted last.  
INS  
INR  
L
L
Document #: 38-06078 Rev. *B  
Page 14 of 18  
   
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Table 1. Non-Contending Read/Write  
Inputs  
Outputs  
CE  
H
X
L
R/W  
X
OE  
X
X
X
X
X
L
UB  
X
H
L
LB  
X
H
H
L
SEM  
H
H
H
H
H
H
H
H
X
I/O9I/O17  
High Z  
I/O0I/O8  
High Z  
Operation  
Deselected: Power Down  
Deselected: Power Down  
Write to Upper Byte Only  
Write to Lower Byte Only  
Write to Both Bytes  
X
High Z  
High Z  
L
Data In  
High Z  
High Z  
L
L
H
L
Data In  
Data In  
High Z  
L
L
L
Data In  
Data Out  
High Z  
L
H
H
H
X
L
H
L
Read Upper Byte Only  
Read Lower Byte Only  
Read Both Bytes  
L
L
H
L
Data Out  
Data Out  
High Z  
L
L
L
Data Out  
High Z  
X
H
X
H
H
L
X
X
H
X
X
X
H
X
Outputs Disabled  
H
H
L
Data Out  
Data Out  
Data In  
Data Out  
Data Out  
Data In  
Read Data in Semaphore Flag  
Read Data in Semaphore Flag  
Write DIN0 into Semaphore Flag  
L
L
X
L
X
X
H
H
L
Data In  
Data In  
Write DIN0 into Semaphore Flag  
L
L
X
X
X
X
L
X
L
L
L
Not Allowed  
Not Allowed  
X
Table 2. Interrupt Operation Example (assumes BUSYL=BUSYR=HIGH)[37]  
Left Port  
Right Port  
Function  
R/WL CEL  
OEL  
X
A0L–14L  
7FFF  
X
INTL R/WR CER  
OER  
X
A0R–14R  
X
INTR  
X
Set Right INTR Flag  
Reset Right INTR Flag  
Set Left INTL Flag  
Reset Left INTL Flag  
L
X
X
X
L
X
X
L
X
X
X
L
X
L
L
X
X
X
L
7FFF  
7FFE  
X
X
X
L[38]  
X
L
7FFE  
X
X
X
Table 3. Semaphore Operation Example  
Function I/O0I/O17 Left I/O0I/O17 Right  
Status  
No action  
1
0
0
1
1
0
1
1
1
0
1
1
1
1
0
0
1
1
0
1
1
1
Semaphore free  
Left port has semaphore token  
Left port writes 0 to semaphore  
Right port writes 0 to semaphore  
Left port writes 1 to semaphore  
Left port writes 0 to semaphore  
Right port writes 1 to semaphore  
Left port writes 1 to semaphore  
Right port writes 0 to semaphore  
Right port writes 1 to semaphore  
Left port writes 0 to semaphore  
No change. Right side has no write access to semaphore  
Right port obtains semaphore token  
No change. Left port has no write access to semaphore  
Left port obtains semaphore token  
Semaphore free  
Right port has semaphore token  
Semaphore free  
Left port has semaphore token  
Semaphore free  
Left port writes 1 to semaphore  
Notes  
37. A  
and A  
,FFFF/FFFE for the CY7C028V/038V.  
0L–15L  
0R–15R  
38. If BUSY =L, then no change.  
R
39. If BUSY =L, then no change.  
L
Document #: 38-06078 Rev. *B  
Page 15 of 18  
           
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Ordering Information  
32K x16 3.3V Asynchronous Dual-Port SRAM  
Speed  
(ns)  
Package  
Operating  
Ordering Code  
CY7C027V-15AC  
Name  
A100  
A100  
A100  
A100  
A100  
A100  
A100  
A100  
Package Type  
Range  
Commercial  
Commercial  
Commercial  
Commercial  
Commercial  
Commercial  
Commercial  
Industrial  
15  
100-Pin Thin Quad Flat Pack  
CY7C027V-15AXC  
CY7C027VN-15AXC  
CY7C027V-20AC  
CY7C027V-20AXC  
CY7C027V-25AC  
CY7C027V-25AXC  
CY7C027AV-25AXI  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
20  
25  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Pb-Free Thin Quad Flat Pack  
64K x16 3.3V Asynchronous Dual-Port SRAM  
Speed  
(ns)  
Package  
Operating  
Range  
Ordering Code  
CY7C028V-15AC  
Name  
A100  
A100  
A100  
A100  
A100  
A100  
A100  
A100  
Package Type  
100-Pin Thin Quad Flat Pack  
15  
Commercial  
Commercial  
Commercial  
Commercial  
Industrial  
CY7C028V-15AXC  
CY7C028V-20AC  
CY7C028V-20AXC  
CY7C028V-20AI  
CY7C028V-20AXI  
CY7C028V-25AC  
CY7C028V-25AXC  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
20  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
Industrial  
25  
Commercial  
Commercial  
100-Pin Pb-Free Thin Quad Flat Pack  
32K x18 3.3V Asynchronous Dual-Port SRAM  
Speed  
(ns)  
Package  
Operating  
Range  
Ordering Code  
CY7C037V-15AC  
Name  
A100  
A100  
A100  
A100  
A100  
A100  
Package Type  
100-Pin Thin Quad Flat Pack  
15  
20  
25  
Commercial  
Commercial  
Commercial  
Commercial  
Commercial  
Commercial  
CY7C037V-15AXC  
CY7C037V-20AC  
CY7C037AV-20AXC  
CY7C037V-25AC  
CY7C037V-25AXC  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
100-Pin Pb-Free Thin Quad Flat Pack  
64K x18 3.3V Asynchronous Dual-Port SRAM  
Speed  
(ns)  
Package  
Operating  
Range  
Ordering Code  
CY7C038V-15AC  
Name  
A100  
A100  
A100  
A100  
A100  
A100  
A100  
A100  
Package Type  
100-Pin Thin Quad Flat Pack  
15  
Commercial  
Commercial  
Commercial  
Commercial  
Industrial  
CY7C038V-15AXC  
CY7C038V-20AC  
CY7C038V-20AXC  
CY7C038V-20AI  
CY7C038V-20AXI  
CY7C038V-25AC  
CY7C038V-25AXC  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
20  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
100-Pin Pb-Free Thin Quad Flat Pack  
100-Pin Thin Quad Flat Pack  
Industrial  
25  
Commercial  
Commercial  
100-Pin Pb-Free Thin Quad Flat Pack  
Document #: 38-06078 Rev. *B  
Page 16 of 18  
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Package Diagram  
Figure 16. 100-Pin Pb-Free Thin Plastic Quad Flat Pack (TQFP) A100  
51-85048-*C  
Document #: 38-06078 Rev. *B  
Page 17 of 18  
CY7C027V/027VN/027AV/028V  
CY7C037V/037AV/038V  
Document History Page  
Document Title: CY7C027V/027VN/027AV/CY7C028V/037V/037AV/038V 3.3V 32K/64K x 16/18 Dual Port Static RAM  
Document Number: 38-06078  
Orig. of  
Change  
Submission  
Date  
Rev.  
ECN No.  
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  
*B  
259110  
JHX  
See ECN Added Pb-Free packaging information.  
2623540  
VKN/PYRS  
12/17/08  
Added CY7C027VN, CY7C027AV and CY7C037AV parts  
Updated Ordering information table  
Sales, Solutions, and Legal Information  
Worldwide Sales and Design Support  
Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. To find the office  
closest to you, visit us at cypress.com/sales.  
Products  
PSoC  
PSoC Solutions  
General  
Low Power/Low Voltage  
Precision Analog  
LCD Drive  
Clocks & Buffers  
Wireless  
Memories  
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Image Sensors  
USB  
© Cypress Semiconductor Corporation, 2001-2008. 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 #: 38-06078 Rev. *B  
Revised December 09, 2008  
Page 18 of 18  
All products and company names mentioned in this document may be the trademarks of their respective holders.  

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