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
VCC to VCC – 0.2V.
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).
tHD
Data Hold From Write End
0
0
0
ns
tHZWE
[9, 10]
R/W LOW to High Z
10
12
15
ns
tLZWE
[9 ,10]
R/W HIGH to Low Z
3
3
3
ns
tWDD
[36]
Write Pulse to Data Delay
30
40
50
ns
tDDD
[36]
Write Data Valid to Read Data Valid
25
30
35
ns
Busy Timing[11]
tBLA
BUSY LOW from Address Match
15
20
20
ns
tBHA
BUSY HIGH from Address Mismatch
15
20
20
ns
tBLC
BUSY LOW from CE LOW
15
20
20
ns
tBHC
BUSY HIGH from CE HIGH
15
16
17
ns
tPS
Port Setup for Priority
5
5
5
ns
tWB
R/W HIGH after BUSY (Slave)
0
0
0
ns
tWH
R/W HIGH after BUSY HIGH (Slave)
13
15
17
ns
tBDD
[13]
BUSY HIGH to Data Valid
15
20
25
ns
Interrupt Timing[11]
tINS
INT Set Time
15
20
20
ns
tINR
INT Reset Time
15
20
20
ns
Semaphore Timing
tSOP
SEM Flag Update Pulse (OE or SEM)
101012
ns
tSWRD
SEM Flag Write to Read Time
5
5
5
ns
tSPS
SEM Flag Contention Window
5
5
5
ns
tSAA
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
ICCDR1
At VCCDR = 2V
50
μA
Data Retention Mode
3.0V
3.0V
VCC > 2.0V
VCC to VCC – 0.2V
VCC
CE
tRC
V
IH
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. tBDD is a calculated parameter and is the greater of tWDD–tPWE (actual) or tDDD–tSD (actual).
14. CE = VCC, Vin = GND to VCC, TA = 25° C. This parameter is guaranteed but not tested.
[+] Feedback
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
