Cypress STK17T88 Computer Hardware User Manual


 
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
A
14
-A
0
Input 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.
DQ
7
-DQ
0
I/O Data: Bi-directional 8-bit data bus for accessing the nvSRAM and RTC.
E Input Chip Enable: The active low E input selects the device.
W
Input 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.
G Input 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.
X
1
Output Crystal Connection, drives crystal on startup.
X
2
Input Crystal Connection for 32.768 kHz crystal.
V
RTCcap
Power Supply Capacitor supplied backup RTC supply voltage (Left unconnected if V
RTCbat
is used).
V
RTCbat
Power Supply Battery supplied backup RTC supply voltage (Left unconnected if V
RTCcap
is used).
V
CC
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)
V
CAP
Power Supply Autostore™ Capacitor: Supplies power to nvSRAM during power loss to store data from SRAM
to nonvolatile storage elements.
V
SS
Power Supply Ground
NC No Connect Unlabeled pins have no internal connections.
Relative PCB Area Usage
[1]
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