Rainbow Electronics DS1543 - Manual

1 of 17 081000
FEATURES
Integrated NV SRAM, real time clock, crystal,
power-fail control circuit and lithium energy
source
Clock registers are accessed identical to the
static RAM. These registers are resident in the
sixteen top RAM locations
Totally nonvolatile with over 10 years of
operation in the absence of power
Precision Power-On Reset
Programmable Watchdog Timer and RTC
Alarm
BCD coded year, month, date, day, hours,
minutes, and seconds with automatic leap year
compensation valid up to the year 2100
Battery voltage level indicator flag
Power-fail write protection allows for
±
10%
Vcc power supply tolerance
Lithium energy source is electrically
disconnected to retain freshness until power is
applied for the first time
ORDERING INFORMATION
DS1543-XXX (5V)
-70
70 ns access
-100 100 ns access
*DS1543W-XXX (3.3V)
-120
120 ns access
-150 150 ns access
PIN ASSIGNMENT
PIN DESCRIPTION
A0-A12 - Address Input
DQ0-DQ7 - Data Input/Outputs
IRQ \FT - Interrupt, Frequency Test
Output (Open-Drain)
RST - Power-On Reset Output
(Open-Drain)
CE - Chip Enable
OE - Output Enable
WE - Write Enable
V
CC
- Power Supply Input
GND - Ground
NC - No Connection
DS1543
64k NV Timekeeping RAM
PRELIMINARY
www.dalsemi.com
V
CC
WE
IRQ/FT
A8
A9
A11
OE
A10
CE
DQ7
DQ6
DQ5
DQ4
DQ3
1
2
3
4
5
6
7
8
9
10
11
12
13
14 RST
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
GND
28
27
26
25
24
23
22
21
20
19
18
17
16
15
28-Pin Encapsulated Package
(700 Mil Extended)