DS17285 Maxim, DS17285 Datasheet - Page 13
![no-image](/images/no-image-200.jpg)
DS17285
Manufacturer Part Number
DS17285
Description
The DS17285, DS17485, DS17885, DS17287, DS17487, and DS17887 real-time clocks (RTCs) are designed to be successors to the industry-standard DS12885 and DS12887
Manufacturer
Maxim
Datasheet
1.DS17285.pdf
(31 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
DS17285-3
Manufacturer:
DALLAS
Quantity:
20 000
Company:
Part Number:
DS17285-5
Manufacturer:
DALLAS
Quantity:
9 756
Part Number:
DS17285S-5
Manufacturer:
DALLAS
Quantity:
20 000
Company:
Part Number:
DS17285S-5+T&R
Manufacturer:
VISHAY
Quantity:
9 910
Company:
Part Number:
DS17285SN-3+
Manufacturer:
Maxim
Quantity:
213
Company:
Part Number:
DS17285SN-5+
Manufacturer:
Freescale
Quantity:
151
Part Number:
DS17285SN-5+
Manufacturer:
DALLAS
Quantity:
20 000
The alarm bytes can be used in two ways. First, when
the alarm time is written in the appropriate hours, min-
utes, and seconds alarm locations, the alarm interrupt
is initiated at the specified time each day, if the alarm
enable bit is high. In this mode, the “0” bits in the alarm
registers and the corresponding time registers must
always be written to 0 (see Table 3A and 3B). Writing
the 0 bits in the alarm and/or time registers to 1 can
result in undefined operation.
The second use condition is to insert a “don’t care”
state in one or more of the alarm bytes. The don’t care
code is any hexadecimal value from C0 to FF. The two
most significant bits of each byte set the don’t care
Table 3A. Time, Calendar, and Alarm Data Modes—BCD Mode (DM = 0)
Note: Unless otherwise specified, the state of the registers is not defined when power is first applied. Except for the seconds regis-
ter, 0 bits in the time and date registers can be written to 1, but can be modified when the clock updates. 0 bits should always be
written to 0 except for alarm mask bits.
Bank 1, 48h
Bank 1, 49h
ADDRESS
0Ah
0Bh
0Ch
0Dh
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
AM/PM
AM/PM
BIT 7
IRQF
SET
VRT
UIP
0
0
0
0
0
0
0
0
0
BIT 6
DV2
PIE
PF
0
0
0
0
0
0
10 Century
10 Year
10 Date
10 Seconds
10 Seconds
10 Minutes
10 Minutes
BIT 5
DV1
AIE
AF
0
0
0
0
0
____________________________________________________________________
10 Hour
10 Hour
10 Date
10 Month
10 Hour
10 Hour
BIT 4
DV0
UIE
UF
0
0
SQWE
BIT 3
RS3
0
0
0
condition when at logic 1. An alarm will be generated
each hour when the “don’t care” bits are set in the
hours byte. Similarly, an alarm is generated every
minute with don’t care codes in the hours and minute
alarm bytes. An alarm is generated every second with
don’t care codes in the hours, minutes, and seconds
alarm bytes.
All 128 bytes can be directly written or read except for
the following:
1) Registers C and D are read-only.
2) Bit 7 of register A is read-only.
3) The MSB of the seconds byte is read-only.
BIT 2
RS2
DM
0
0
Seconds
Seconds
Minutes
Minutes
Century
Hours
Hours
Month
Date
Year
Date
BIT 1
24/12
Day
RS1
0
0
Real-Time Clocks
BIT 0
RS0
DSE
0
0
Seconds Alarm
Minutes Alarm
Hours Alarm
FUNCTION
Date Alarm
Seconds
Minutes
Century
Control
Control
Control
Control
Month
Hours
Date
Year
Day
1–12 +AM/PM
1–12 +AM/PM
RANGE
00–59
00–59
00–59
00–59
00–23
00–23
01–07
01–31
01–12
00–99
00–99
01–31
—
—
—
—
13