DS2422 Maxim, DS2422 Datasheet - Page 16

• Manufacturer Part Number: DS2422
• Description: The DS2422 temperature/data logger combines the core functions of a fully featured data logger in a single chip
• Manufacturer: Maxim

Register Details
REAL-TIME CLOCK CONTROL
To minimize the power consumption of a battery-operated datalogger, the RTC oscillator should be turned off when
device is not in use. The oscillator on/off bit is located in the RTC control register. This register also includes the
EHSS bit, which determines whether the sample rate is specified in seconds or minutes.
RTC Control Register Bitmap
During a mission, there is only read access to this register. Bits 2-7 have no function. They always read 0 and
cannot be written to 1.
Register Details
EDLA: Enable Data Low
Alarm
EDHA: Enable Data High
Alarm
EOSC: Enable Oscillator
EHSS: Enable High Speed
Sample
ADDR
0212h
BIT DESCRIPTION
BIT DESCRIPTION
b7
0
b6
0
BIT(S)
BIT(S)
b5
b0
b1
0
b0
b1
This bit controls whether, during a mission, the Data Low Alarm Flag
DLF may be set, if a data value from the serial data interface is equal to
or lower than the value in the Data Low Alarm Threshold Register. If
EDLA is 1, data low alarms are enabled. If EDLA is 0, data low alarms
are not generated.
This bit controls whether, during a mission, the Data High Alarm Flag
DHF may be set, if a data value from the serial data interface is equal to
or higher than the value in the Data High Alarm Threshold Register. If
EDHA is 1, data high alarms are enabled. If EDHA is 0, data high
alarms are not generated.
This bit controls the crystal oscillator of the RTC. When set to logic 1,
the oscillator will start operation. When written to logic 0, the oscillator
stops and the device is in a low-power data retention mode. This bit
must be 1 for normal operation. A Forced Conversion or Start Mission
command automatically starts the RTC by changing the EOSC bit to
logic 1.
This bit controls the speed of the Sample Rate counter. When set to
logic 0, the sample rate is specified in minutes. When set to logic 1, the
sample rate is specified in seconds.
b4
0
16 of 49
b3
0
b2
0
EHSS
DEFINITION
DEFINITION
b1
EOSC
b0