DS17287-5+ Maxim Integrated Products, DS17287-5+ Datasheet - Page 16

• Manufacturer Part Number: DS17287-5+
• Description: IC RTC 5V 2K NV RAM 24-EDIP
• Manufacturer: Maxim Integrated Products
• Type: Clock/Calendar/NVSRAMr

Specifications of DS17287-5+

• Memory Size: 16K (2K x 8)
• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 24-DIP (600 mil) Module
• Function: Clock/Calendar/Alarm
• Rtc Memory Size: 2048 Byte
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Rtc Bus Interface: Multiplexed
• Supply Current: 25 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Real-Time Clocks
Bit 7: SET. When the SET bit is 0, the update transfer
functions normally by advancing the counts once per
second. When the SET bit is written to 1, any update
transfer is inhibited, and the program can initialize the
time and calendar bytes without an update occurring in
the midst of initializing. Read cycles can be executed in
a similar manner. SET is a read/write bit and is not
affected by any internal functions of the DS17x85.
Bit 6: Periodic Interrupt Enable (PIE). This bit is a
read/write bit that allows the periodic interrupt flag (PF)
bit in Register C to drive the IRQ pin low. When PIE is
set to 1, periodic interrupts are generated by driving
the IRQ pin low at a rate specified by the RS3–RS0 bits
of Register A. A 0 in the PIE bit blocks the IRQ output
from being driven by a periodic interrupt, but the PF bit
is still set at the periodic rate. PIE is not modified by
any internal DS17x85 functions.
Bit 5: Alarm Interrupt Enable (AIE). This bit is a
read/write bit that, when set to 1, permits the alarm flag
(AF) bit in Register C to assert IRQ. An alarm interrupt
occurs for each second that the three time bytes equal
the three alarm bytes, including a don’t care alarm
code of binary 11XXXXXX. When the AIE bit is set to 0,
the AF bit does not initiate the IRQ signal. The internal
functions of the DS17x285/87 do not affect the AIE bit.
Bit 4: Update-Ended Interrupt Enable (UIE). This bit is
a read/write bit that enables the update-end flag (UF)
bit in Register C to assert IRQ. The SET bit going high
clears the UIE bit.
Register B (0Bh)
MSB
16
BIT 7
SET
____________________________________________________________________
BIT 6
PIE
BIT 5
AIE
BIT 4
UIE
Bit 3: Square-Wave Enable (SQWE). When this bit is
set to 1 and E32k = 0, a square-wave signal at the fre-
quency set by RS3–RS0 is driven out on the SQW pin.
When the SQWE bit is set to 0 and E32k = 0, the SQW
pin is held low. SQWE is a read/write bit. SQWE is set
to 1 when V
Bit 2: Data Mode (DM). This bit indicates whether time
and calendar information is in binary or BCD format.
The program sets the DM bit to the appropriate format
and can be read as required. This bit is not modified by
internal functions. A 1 in DM signifies binary data, while
a 0 in DM specifies binary-coded decimal (BCD) data.
Bit 1: 24/12 Control (24/12). This bit establishes the
format of the hours byte. A 1 indicates the 24-hour
mode and a 0 indicates the 12-hour mode. This bit is
read/write and is not affected by internal functions.
Bit 0: Daylight Saving Enable (DSE). This bit is a
read/write bit that enables two daylight saving adjust-
ments when DSE is set to 1. On the first Sunday in
April, the time increments from 1:59:59AM to
3:00:00AM. On the last Sunday in October when the
time first reaches 1:59:59AM, it changes to 1:00:00AM.
When DSE is enabled, the internal logic tests for the
first/last Sunday condition at midnight. If the DSE bit is
not set when the test occurs, the daylight saving func-
tion does not operate correctly. These adjustments do
not occur when the DSE bit is zero. This bit is not
affected by internal functions.
SQWE
BIT 3
CC
is powered up.
BIT 2
DM
BIT 1
24/12
BIT 0
DSE
LSB