STK22C48
Document Number: 001-51000 Rev. **
Page 2 of 14
Pin Configurations
Figure 1. Pin Diagram - 28-Pin SOIC
Table 1. Pin Definitions
Pin Name
Alt
IO Type
Description
A
0
–A
10
Input
Address Inputs.
Used to select one of the 2,048 bytes of the nvSRAM.
DQ
0
-DQ
7
Input or Output
Bidirectional Data IO Lines
. Used as input or output lines depending on operation.
WE
W
Input
Write Enable Input, Active LOW
. When the chip is enabled and WE is LOW, data on the IO
pins is written to the specific address location.
CE
E
Input
Chip Enable Input, Active LOW
. When LOW, selects the chip. When HIGH, deselects the chip.
OE
G
Input
Output Enable, Active LOW
. The active LOW OE input enables the data output buffers during
read cycles. Deasserting OE HIGH causes the IO pins to tri-state.
V
SS
Ground
Ground for the Device
.
The device is connected to ground of the system.
V
CC
Power Supply
Power Supply Inputs to the Device
.
HSB
Input or Output
Hardware Store Busy (HSB)
. When LOW, this output indicates a Hardware Store is in progress.
When pulled low external to the chip, it initiates a nonvolatile STORE operation. A weak internal
pull up resistor keeps this pin high if not connected (connection optional).
V
CAP
Power Supply
AutoStore
Capacitor
. Supplies power to nvSRAM during power loss to store data from SRAM
to nonvolatile elements.
NC
No Connect
No Connect
. This pin is not connected to the die.
V
CAP
A
7
A
6
A
5
A
4
V
CC
HSB
WE
A
8
A
9
OE
A
10
DQ6
DQ7
DQ5
CE
DQ4
DQ3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
V
SS
DQ0
A
3
A
2
A
1
A
0
DQ1
DQ2
28-SOIC
Top View
(Not To Scale)
NC
NC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
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