DS1338Z-33+ Maxim Integrated Products, DS1338Z-33+ Datasheet - Page 10

• Manufacturer Part Number: DS1338Z-33+
• Description: IC RTC 56BYTE NV RAM 3.3V 8-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Clock/Calendar/NVSRAMr

Specifications of DS1338Z-33+

• Memory Size: 56B
• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Function: Clock/Calendar
• Rtc Memory Size: 56 Byte
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Rtc Bus Interface: Serial (I2C)
• Supply Current: 325 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

whenever the seconds register is written. Write transfers occur on the acknowledge from the DS1338. Once the
countdown chain is reset, to avoid rollover issues the remaining time and date registers must be written within
1 second. The 1Hz square-wave output, if enabled, transitions high 500ms after the seconds data transfer,
provided the oscillator is already running.
The DS1338 runs in either 12-hour or 24-hour mode. Bit 6 of the hours register is defined as the 12-hour or 24-hour
mode-select bit. When high, the 12-hour mode is selected. In the 12-hour mode, bit 5 is the AM/PM bit, with logic
high being PM. In the 24-hour mode, bit 5 is the second 10-hour bit (20–23 hours). If the 12/24-hour mode select is
changed, the hours register must be re-initialized to the new format.
On an I
these secondary registers, while the clock continues to run. This eliminates the need to re-read the registers in
case of an update of the main registers during a read.
Table 3. RTC and RAM Address Map
Note: Bits listed as “0” always read as a 0.
ADDRESS
08H–3FH
00H
01H
02H
03H
04H
05H
06H
07H
2
C START, the current time is transferred to a second set of registers. The time information is read from
BIT 7
OUT
CH
0
0
0
0
0
BIT 6
12/24
0
0
0
0
10 Year
10 Seconds
10 Minutes
10 Hour
AM/PM
BIT 5
OSF
0
0
10 Date
SQWE
Month
BIT 4
Hour
10
10
0
BIT 3
10 of 16
0
0
BIT 2
Seconds
0
Minutes
Month
Hour
Date
Year
BIT 1
RS1
Day
DS1338 I
BIT 0
RS0
2
C RTC with 56-Byte NV RAM
FUNCTION
RAM 56 x 8
Seconds
Minutes
Control
Month
Hours
Date
Year
Day
00H–FFH
+AM/PM
RANGE
00–59
00–59
00–23
01–31
01–12
00–99
1–12
1–7