SM8580 Nippon_Precision_Circuits America, SM8580 Datasheet - Page 3

• Manufacturer Part Number: SM8580
• Description: Real-time Clock ic
• Manufacturer: Nippon_Precision_Circuits America

PIN DESCRIPTION
1. Connect a 0.1µF capacitor between VDD and VSS.
Number
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
1
2
3
4
5
6
7
8
9
VTEMP
AIRQN
TIRQN
FCON
Name
CE0N
FOUT
WRN
RDN
VDD
VSS
CE1
XTN
NC
NC
NC
D3
D2
D1
D0
XT
A0
A1
A2
A3
I/O
I/O
I/O
I/O
I/O
O
O
O
O
O
–
–
–
–
–
I
I
I
I
I
I
I
I
I
I
Chip enable 0 input with built-in pull-up resistor.
The SM8580AM can be accessed when CE0N is LOW and CE1 is HIGH.
FOUT output frequency select control input (when CE1 is HIGH).
32.768kHz fixed frequency output when FCON is LOW.
Output frequency determined by bit FD when FCON is HIGH (when FE bit is 1).
Note that a HIGH-level voltage should be applied to FCON to avoid unwanted 32.768kHz output during
backup.
Frequency set register, frequency output (CMOS output)
Temperature voltage output (analog output)
Alarm interrupt output (N-channel open-drain output)
Timer interrupt output (N-channel open-drain output)
Address inputs.
Connect to the microcontroller address bus.
The selected register address is input on this bus when accessing the SM8580AM (positive logic).
Read strobe input. Data can be read from SM8580AM when RDN is LOW and WRN is HIGH.
An error will occur if both RDN and WRN are simultaneously LOW.
Ground
Write strobe input. Data can be written to SM8580AM when RDN is HIGH and WRN is LOW.
An error will occur if both RDN and WRN are simultaneously LOW.
Data bus input/outputs.
Connect to the microcontroller data bus.
Chip enable 1 input with built-in pull-down resistor.
The SM8580AM can be accessed when CE0N is LOW and CE1 is HIGH.
FOUT is in output mode when CE1 is HIGH, regardless of the state of CE0N. FOUT is high impedance
when CE1 is LOW.
No connection
No connection
No connection
Oscillator output, with built-in oscillator capacitance C
Oscillator output, with built-in oscillator capacitance C
Supply
SM8580AM
Function
NIPPON PRECISION CIRCUITS INC.—3
D
G
1