PCMCIA SRAM Memory Card
SRA Series
SRAM Memory Card
General Description
The WEDC SRAM Series (SRA) memory cards offer a
high performance nonvolatile storage solution for code
and data storage, disk caching, and write intensive
mobile and embedded applications.
Packaged in PCMCIA type I or type II housing (type II
for cards with extended battery backup time), the
WEDC SRAM SRA series is based on 1 or 4Mbit
SRAM memories, providing densities from 256
Kilobytes to 8 Megabytes.
The SRA series of SRAM memory cards requires a 5V
power supply and operates at speeds to 150ns. The
cards are based on advanced CMOS technology
providing very low power and reliable data retention
characteristics. WEDC’s SRAM cards contain a
rechargeable lithium battery and recharge circuitry,
eliminating the need for replaceable batteries found in
many SRAM cards.
WEDC’s standard cards are shipped with WEDC’s
SRAM Logo. Cards are also available with blank
housings (no Logo). The blank housings are available
in both a recessed (for label) and flat housing. Please
contact WEDC sales representative for further
information on Custom artwork.
256KB through 8MB
Features
•
High Performance SRAM memory Card
• Single 5 Volt Supply
- (3.3V/5V operation is available as an option)
• Fast Access times: 150ns
• x8/x16 PCMCIA standard interface
• Low Power CMOS technology provides very low
power and reliable data retention characteristics
- standby current < 100µA typical
• Rechargeable Lithium battery with recharge circuitry
- eliminates the need for replaceable batteries
- standby current during recharge typically < 2mA
- battery backup time
•7 months - type I card
•18 months - type II card
typical based on 4MB (lower densities will
have greater storage times)
• Unlimited write cycles, no endurance issues
• Optional Features:
• 2KB EEPROM attribute memory containing
CIS
• Optional Hardware Write Protect switch
• PC Card Standard Type I or Type II Form Factor
Block Diagram
4MB SRAM Card Shown
[A1..A19]
address
buffer
SRAM
512K x 8
[A20..A22]
/CSHi
+ + + + +
CE1#
CE2#
WE#
OE#
REG#
A0
decoder
and
control
logic
/CSLi
/CS-A
/RD
/RD
/WR
/WR
CTRL
SRAM
512K x 8
SRAM
512K x 8
SRAM
512K x 8
SRAM
512K x 8
SRAM
512K x 8
SRAM
512K x 8
SRAM
512K x 8
/CSHi
[A1..A11]
S1
WP
Write Prot
Switch
VS1
VS2
GND
NC
NC
Vcc
/CS-A
/RD
/WR
ATTRIBUTE
MEMORY
CTRL
I/O BUFFER
[DO..D7]
[DO..D7]
[D8..D15]
+
BVD1
BVD2
Vcc
[D8..D15]
Power Management
and
Battery Control
Notes:
to internal
power
supply
1. pull down resistor (min 100k)
+
2. pull up resistor (min 10k)
Lithium Bat.
February 2002 Rev. 6
1
PC Card Products
PCMCIA SRAM Memory Card
SRA Series
Pinout
Pin Signal name
1
GND
2
DQ3
3
DQ4
4
DQ5
5
DQ6
6
DQ7
7
CE1#
8
A10
9
OE#
10
A11
11
A9
12
A8
13
A13
14
A14
15
WE#
16 RDY/BSY#
17
Vcc
18
Vpp1
19
A16
20
A15
21
A12
22
A7
23
A6
24
A5
25
A4
26
A3
27
A2
28
A1
29
A0
30
DQ0
31
DQ1
32
DQ2
33
WP
34
GND
I/O
I/O
I/O
I/O
I/O
I/O
I
I
I
I
I
I
I
I
I
O
Function
Ground
Data bit 3
Data bit 4
Data bit 5
Data bit 6
Data bit 7
Card enable 1
Address bit 10
Output enable
Address bit 11
Address bit 9
Address bit 8
Address bit 13
Address bit 14
Write Enable
Ready/Busy
Supply Voltage
Prog. Voltage
Address bit 16
Address bit 15
Address bit 12
Address bit 7
Address bit 6
Address bit 5
Address bit 4
Address bit 3
Address bit 2
Address bit 1
Address bit 0
Data bit 0
Data bit 1
Data bit 2
Write Potect
Ground
Active
Pin Signal name
35
GND
36
CD1#
37
DQ11
38
DQ12
39
DQ13
40
DQ14
41
DQ15
42
CE2#
43
VS1
44
N.C.
45
N.C.
46
A17
47
A18
48
A19
49
A20
50
A21
51
Vcc
52
Vpp2
53
A22
54
A23
55
A24
56
A25
57
VS2
58
N.C.
59
Wait#
60
N.C.
61
REG#
62
BVD2
63
BVD1
64
DQ8
65
DQ9
66
DQ10
67
CD2#
68
GND
I/O
O
I/O
I/O
I/O
I/O
I
I
O
Function
Ground
Card Detect 1
Data bit 11
Data bit 12
Data bit 13
Data bit 14
Data bit 15
Card Enable 2
Voltage Sense 1
Active
LOW
LOW
LOW
LOW
N.C.
LOW
N.C.
N.C.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I/O
I/O
I/O
O
O
O
I
O
O
I/O
I/O
O
O
Address bit 17 256KB(2)
Address bit 18 512KB(2)
Address bit 19
1MB(2)
Address bit 20
2MB(2)
Address bit 21
4MB(2)
Supply Voltage
Prog. Voltage
N.C.
Address bit 22 8MB(2,4)
N.C.
N.C.
N.C.
Voltage Sense 2
N.C.
Extended Bus Cycle
Attrib Mem Select
Bat. Volt. Detect 2
Bat. Volt. Detect 1
Data bit 8
Data bit 9
Data bit 10
Card Detect 2
Ground
Low
Low
(3)
HIGH
LOW
Notes:
1. CD1# and CD2# are grounded internal to PC Card.
2. Shows density for which specified address bit is MSB. Higher order address bits are
no connects (i.e., 1MB A19 is MSB, A20 - A21 are NC).
3. BVD1 is an open drain output with a 10K ohm internal pull-up resistor.
4. Address bit 22 is used for the 8MB cards as well as the 6MB Cards.
February 2002 Rev. 6
2
PC Card Products
PCMCIA SRAM Memory Card
SRA Series
Mechanical
Type I
Interconnect area
1.6mm
±
0.05
(0.063”)
10.0mm MIN
(0.400”)
3.0mm MIN
1.0mm
±
0.05
(0.039”)
Substrate area
54.0mm
±
0.10
(2.126”)
1.0mm
±
0.05
(0.039”)
85.6mm
±
0.20
(3.370”)
10.0mm MIN
(0.400”)
3.3mm
±
T1 (0.130”)
T1=0.10mm interconnect area
T1=0.20mm substrate area
Type II
1.6mm
±
0.05
0.063”
85.6mm
±
0.20
3.370”
1.0mm
±0.05
0.039’
3.0mm
MIN.
Substrate area
54.0mm
±
0.10
2.126”
1.0mm
±0.05
0.039’
10.0mm MIN
0.400”
Interconnect area
5.0mm
±
T1
0.197”
February 2002 Rev. 6
3
PC Card Products
PCMCIA SRAM Memory Card
SRA Series
Card Signal Description
Symbol
A0 - A25
Type
INPUT
Name and Function
ADDRESS INPUTS:
A0 through A25 enable direct addressing of up
to 64MB of memory on the card. Signal A0 is not used in word access
mode. A25 is the most significant bit. (address pins used are based on
card density,see pinout for highest used address pin)
DATA INPUT/OUTPUT:
DQ0 THROUGH DQ15 constitute the
bi-directional databus. DQ0 - DQ7 constitute the lower (even) byte and
DQ8 - DQ15 the upper (odd) byte. DQ15 is the MSB.
CARD ENABLE 1 AND 2:
CE1# enables even byte accesses, CE2#
enables odd byte accesses. Multiplexing A0, CE1# and CE2# allows 8-
bit hosts to access all data on DQ0 - DQ7.
OUTPUT ENABLE:
Active low signal enabling read data from the
memory card.
WRITE ENABLE:
Active low signal gating write data to the memory
card.
READY/BUSY OUTPUT:
Not used for SRAM cards
CARD DETECT 1 and 2:
Provide card insertion detection. These
signals are connected to ground internally on the memory card. The
host socket interface circuitry shall supply 10K-ohm or larger pull-up
resistors on these signal pins.
WRITE PROTECT:
Follows hardware Write Protect Switch. When
Switch is placed in on position, signal is pulled high (10K ohm). When
switch is off signal is pulled low.
PROGRAM/ERASE POWER SUPPLY:
Not used for SRAM
cards.
CARD POWER SUPPLY:
5.0V for all internal circuitry.
GROUND:
for all internal circuitry.
ATTRIBUTE MEMORY SELECT :
only used with cards built with
optional attribute memory.
RESET:
Not used for SRAM cards
WAIT:
This signal is pulled high internally for compatibility. No wait
states are generated.
BATTERY VOLTAGE DETECT:
Provides status of Battery
voltage.
BVD2 = BVD1 = Voh (battery voltage is guaranteed to retain data)
BVD2 = Vol, BVD1 = Voh (data is valid, battery recharge required)
BVD2 = BVD1 = Vol (data may no longer be valid, battery requires
extended recharge)
VOLTAGE SENSE:
Notifies the host socket of the card's VCC
requirements. VS1 and VS2 are open to indicate a 5V, 16 bit card has
been inserted.
RESERVED FOR FUTURE USE
NO INTERNAL CONNECTION TO CARD:
pin may be driven
or left floating
DQ0 - DQ15
CE1#, CE2#
OE#
WE#
RDY/BSY#
CD1#, CD2#
INPUT/OUT
PUT
INPUT
INPUT
INPUT
OUTPUT
OUTPUT
WP
VPP1, VPP2
VCC
GND
REG#
RST
WAIT#
BVD1, BVD2
OUTPUT
N.C.
INPUT
INPUT
OUTPUT
OUTPUT
VS1, VS2
RFU
N.C.
OUTPUT
FUNCTIONAL TRUTH TABLE
READ function
Function Mode
/CE2 /CE1
Standby Mode
H
H
Byte Access (8 bits)
H
L
H
L
Word Access (16 bits)
L
L
Odd-Byte Only Access
L
H
WRITE function
Standby Mode
H
H
Byte Access (8 bits)
H
L
H
L
Word Access (16 bits)
L
L
Odd-Byte Only Access
L
H
A0
X
L
H
X
X
X
L
H
X
X
/OE
X
L
L
L
L
X
H
H
H
H
/WE
X
H
H
H
H
X
L
L
L
L
Common Memory
/REG D15-D8
D7-D0
X
High-Z
High-Z
H
High-Z Even-Byte
H
High-Z Odd-Byte
H Odd-Byte Even-Byte
H Odd-Byte High-Z
X
H
H
H
H
X
X
X
Even-Byte
X
Odd-Byte
Odd-Byte Even-Byte
Odd-Byte
X
Attribute Memory
/REG D15-D8
D7-D0
X
High-Z
High-Z
L
High-Z Even-Byte
L
High-Z Not Valid
L Not Valid Even-Byte
L Not Valid
High-Z
X
L
L
L
L
X
X
X
X
X
X
Even-Byte
X
Even-Byte
X
February 2002 Rev. 6
4
PC Card Products
PCMCIA SRAM Memory Card
SRA Series
Absolute Maximum Ratings
(2)
Operating Temperature TA (ambient)
Commercial
Industrial
Storage Temperature
Commercial
Industrial
Voltage on any pin relative to VSS
VCC supply Voltage relative to VSS
0°C to +60 °C
-40°C to +85 °C
0°C to +60 °C
-40°C to +85 °C
-0.5V to VCC+0.5V (1)
-0.5V to +7.0V
Notes:
(1) During transitions, inputs may undershoot to
-2.0V or overshoot to VCC +2.0V for periods
less than 20ns.
(2) Stress greater than those listed under
“Absolute Maximum ratings” may cause
permanent damage to the device. This is a
stress rating only and functional operation at
these or any other conditions greater than those
indicated in the operational sections of this
specification is not implied. Exposure to
absolute maximum rating conditions for
extended periods may affect reliability.
DC Characteristics
(1)
CMOS Test Conditions: VIL = VSS ± 0.2V, VIH = VCC ± 0.2V
Sym
ICC
Parameter
VCC Active Current
Density
64KB
128KB
256KB
512KB
1MB
to
8MB
All
All
All
All
All
All
All
Notes
1
Min
Typ
90
90
90
90
110
(3)
Max
180
180
180
180
190
Units
mA
Test Conditions
VCC = 5.25V
tcycle = 150ns
ICCS
ILI
ILO
VIL
VIH
VOL
VOH
VCC Standby Current
Input Leakage Current
Output Leakage Current
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
2,4
5,6
6
6
6
6
6
< 0.1
<1
10
±20
±20
mA
µA
µA
V
V
V
V
VCC = 5.25V
Control Signals = VCC
VCC = VCCMAX
Vin =VCC or VSS
VCC = VCCMAX
Vout =VCC or VSS
0
3.85
0.8
VCC
+0.5
0.4
VCC
IOL = 3.2mA
IOH = -2.0mA
VCC-
0.4
Notes:
1. All currents are for x16 mode and are RMS values unless otherwise specified.
2. Control Signals: CE
1
#, CE
2
#, OE#, WE#, REG#.
3. Typical: VCC = 5V, T = +25C.
4. ICCS includes battery recharge current. Value depends on battery discharge level. ICCS min is specified for fully
charged battery. ICCS typical value is specified for battery discharge to 2.7V. ICCS max is specified for a fully
discharged battery (0V). Battery will recharge to 1.5V in 20 sec.
5. Values are the same for byte and word wide modes for all card densities.
6. Exceptions: Leakage currents on CE1#, CE2#, OE#, REG# and WE# will be < 500 µA when VIN = GND due to
internal pull-up resistors.
Battery Characteristics
Parameter
Battery Life
Density
All
256KB
512KB, 1MB
2MB
4MB
6MB
8MB
Notes
(1)
(2)
SRA11-14
Type I
min 10
-
32
22
12
12
-
SRA01-04
Type I Type II
Units
min 10
years
24
60
18
45
12
30
months
7
17
(typical)
17
7
12
-
Conditions
Normal operation, T=25C
T=25C
Battery backup time is a
calculated value and is not
guaranteed. This should
not be used to schedule
battery recharging.
Battery
Backup Time
Notes:
1. Battery Life refers to functional lifetime of battery.
2. Battery backup time is density and temperature dependent.
February 2002 Rev. 6
5
PC Card Products
Microchip MCU
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