DS1922T-F5# Maxim Integrated Products, DS1922T-F5# Datasheet - Page 24

• Manufacturer Part Number: DS1922T-F5#
• Description: IBUTTON TEMP LOGGER
• Manufacturer: Maxim Integrated Products
• Series: iButton®r

Specifications of DS1922T-F5#

• Rohs Information: IButton RoHS Compliance Plan
• Memory Size: 512B
• Memory Type: NVSRAM (Non-Volatile SRAM)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Temperature Logger iButton with 8KB
Data-Log Memory
The content of the Mission Start Delay Counter register
tells how many minutes must expire from the time a
mission was started until the first measurement of the
mission takes place (SUTA = 0) or until the device
starts testing the temperature for a temperature alarm
(SUTA = 1). The Mission Start Delay is stored as an
unsigned 24-bit integer number. The maximum delay is
16,777,215min, equivalent to 11,650 days or roughly 31
years. If the start delay is nonzero and the SUTA bit is
set to 1, first the delay must expire before the device
starts testing for temperature alarms to begin logging
data.
For a typical mission, the Mission Start Delay is 0. If a
mission is too long for a single DS1922L/DS1922T to
store all readings at the selected sample rate, one can
use several devices and set the Mission Start Delay for
the second device to start recording as soon as the
memory of the first device is full, and so on. The RO bit
in the Mission Control register (address 0213h) must be
set to 0 to prevent overwriting of collected data once
the data-log memory is full.
Note: During a mission, there is only read access to this register.
Note: There is only read access to this register.
Note: There is only read access to this register.
24
ADDRESS
ADDRESS
ADDRESS
021Ah
021Bh
021Ch
021Dh
0216h
0217h
0218h
0219h
021Eh
0220h
0221h
0222h
______________________________________________________________________________________
CENT
BIT 7
BIT 7
BIT 7
0
0
0
0
12/24
BIT 6
BIT 6
BIT 6
Mission Start Delay
0
0
10 Years
10 Seconds
10 Minutes
20 Hours
AM/PM
BIT 5
BIT 5
BIT 5
0
10 Date
10 Months
10 Hours
BIT 4
BIT 4
BIT 4
Delay Center Byte
Delay High Byte
Delay Low Byte
Mission Start Delay Counter Register Bitmap
Center Byte
High Byte
Low Byte
The Mission Timestamp register indicates the date and
time of the first temperature sample of the mission.
There is only read access to the Mission Timestamp
register.
Depending on settings in the Mission Control register
(address 0213h), the DS1922L/DS1922T log tempera-
ture in 8-bit or 16-bit format. The Mission Samples
Counter together with the starting address and the log-
ging format (8 or 16 bits) provide the information to iden-
tify valid blocks of data that have been gathered during
the current (MIP = 1) or latest mission (MIP = 0). See the
Data-Log Memory Usage section for an illustration.
The number read from the Mission Samples Counter
indicates how often the DS1922L/DS1922T woke up
during a mission to measure temperature. The number
format is 24-bit unsigned integer. The Mission Samples
Counter is reset through the Clear Memory command.
Mission Samples Counter Register Bitmap
BIT 3
BIT 3
BIT 3
Mission Timestamp Register Bitmap
Mission Progress Indicator
BIT 2
BIT 2
BIT 2
Single Seconds
Single Minutes
Single Months
Single Hours
Single Years
Single Date
Mission Timestamp
BIT 1
BIT 1
BIT 1
BIT 0
BIT 0
BIT 0