STK17T88

Document Number: 001-52040 Rev. *A Page 2 of 22

Pin Configurations

Figure 1. 48-Pin SSOP

V
SS
A
14
A
12
A
7
A
6
DQ
0
DQ
1
V
CC
DQ
2
A
3
A
2
A
1
V
CAP
A
13
A
6
A
9
A
11
A
10
DQ
7
DQ
6
V
SS
A
0
NC
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
NC
E
X
1
X
2
23
24
A
5
INT
NC
NC
NC
NC
A
4
48
47
46
45
V
CC
HSB
NC
NC
W
NC
DQ
5
DQ
3
DQ
4
G
CNCN
V
RTCbat
V
RTCcap

(TOP)

Note
1. For detailed package size specifications, see Package Diagram on page 21.
Pin Descriptions

Pin Name IO Type Description

A14-A0Input Address: The 15 address inputs select one of 32,768 bytes in the nvSRAM array or one of 16 bytes

in the clock register map.

DQ7-DQ0I/O Data: Bi-directional 8-bit data bus for accessing the nvSRAM and RTC.

EInput Chip Enable: The active low E input selects the device.

WInput Write Enable: The active low W enables data on the DQ pins to be written to the address location

selected on the falling edge of E.

GInput Output Enable: The active low G input enables the data output buffers during read cycles.

De-asserting G high caused the DQ pins to tri-state.

X1Output Crystal Connection, drives crystal on startup.

X2Input Crystal Connection for 32.768 kHz crystal.

VRTCcap Power Supply Capacitor supplied backup RTC supply voltage (Left unconnected if VRTCbat is used).

VRTCbat Power Supply Battery supplied backup RTC supply voltage (Left unconnected if VRTCcap is used).

VCC Power Supply Power: 3.0V, +20%, -10%

HSB I/O Hardware Store Busy: When low this output indicates a Store is in progress. When pulled low

external to the chip, it initiates a nonvolatile STORE operation. A weak pull up resistor keeps this

pin high if not connected. (Connection Optional).

INT Output Interrupt Control: Can be programmed to respond to the clock alarm, the watchdog timer and the

power monitor. Programmable to either active high (push/pull) or active low (open-drain)

VCAP Power Supply Autostore™ Capacitor: Supplies power to nvSRAM during power loss to store data from SRAM

to nonvolatile storage elements.

VSS Power Supply Ground

NC No Connect Unlabeled pins have no internal connections.

Relative PCB Area Usage[1]
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