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052300
FEATURES
Measures four channels of data:
-
Integrated 8-bit temperature sensor,
-
Integrated 8-bit Analog-to-Digital Converter
(ADC) with a three input mux for measuring
up to three external sensors
Digital thermometer measures temperature
-40
C to +85
C in 0.5
C increments (-40
F to
+183.2
F in 0.9
F increments)
Digital thermometer provides
2
C accuracy
Real Time Clock/Calendar in BCD format counts
seconds, minutes, hours, date, month, day of the
week, and year with leap year compensation. The
Real Time Clock is fully Y2K-compliant
Automatically wakes up and measures
temperature and/or ADC data at user-
programmable intervals from 1 to 255 minutes
2048-byte datalog memory
Records long-term temperature histogram in
63 bins with 2.0
C resolution
Records long-term ADC data histogram in 64 bins
with 4-bit resolution/bin (32 mV/bin) for ADC
Channel One
Programmable temperature-high and -low alarm
trip points
Programmable ADC data-high and -low alarm trip
points
Records time stamp and duration when
temperature or ADC Channel 1 Data leaves the
interval specified by the trip points
Two serial interface options: synchronous and
asynchronous
- 3-wire synchronous serial interface
- Asynchronous serial interface compatible with
standard UARTs
Memory partitioned into 32 byte pages for
packetizing data
On-chip 16-bit CRC generator to safeguard data
read operations in asynchronous communications
mode
Unique, factory lasered 64-bit serial number
PIN ASSIGNMENT
PIN DESCRIPTION
V
bat
- Battery Supply
X1
- Crystal Input
X2
- Crystal Output
AINx
- Analog in
INSPEC
- In-specification Output
OUTSPEC
- Out-of-specification Output
INT
- Interrupt Output
GND
- Digital Ground
AGND
- Analog Ground
ST
- Start/Status Input
RST
- 3-wire Reset Input
I/O
- 3-wire Input/Output
SCLK
- 3-wire Clock Input
TX
- Transmit Output
RX
- Receive Input
COMSEL
- Communication Select
V
CC
- +5V Supply
ORDERING INFORMATION
DS1616
24-Pin DIP
DS1616S
24-Pin SOIC
DS1616
Temperature and Three Input
MUX'ed 8-bit Data Recorder
www.dalsemi.com
1
2
3
4
5
6
7
8
17
18
19
20
21
22
23
24
V
BAT
V
CC
AIN3
INT
COMSEL
RX
TX
SCLK
I/O
RST
ST
OUTSPEC
INSPEC
AIN1
X2
X1
15
16
10
9
AIN2
NC
AGND
13
14
12
11
N/C
NC
GND
GND
GND
DS1616 24-Pin DIP (600 mil)
DS1616S 24-Pin SOIC (300 mil)
PRELIMINARY
DS1616
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DESCRIPTION
The DS1616 is an integrated temperature/data recorder. It combines a Real Time Clock (RTC),
temperature sensor, and a three input mux'ed 8-bit Analog-to-Digital Converter (ADC). Datalogging is
supported for all four data channels and the and histogram functionality is supported for the temperature
sensor and ADC Channel 1 only. A programmable sample rate feature makes the device ideal for
applications requiring datalogging over short or long time frames.
The RTC provides seconds, minutes, hours, day, date, month, and year information with leap year
compensation, Year 2000 compliance, and also provides an alarm interrupt. Temperature measurement is
provided via integrated thermal technology which can measure temperatures from -40
C to +85
C in
0.5
C increments. An integrated three input mux'ed 8-bit ADC allows the device to record data from
other types of sensors.
The datalog function simply samples data at a user-defined sample rate and writes the data to the Datalog
memory. A total of 2048 bytes of data may be recorded. If only one data channel is selected, a total of
2048 samples can be recorded for that channel. If two channels are enabled, each channel can record
1024 samples. If three or four channels are enabled, each channel can record 512 samples. In the case of
only three channels enabled, the location corresponding to the disabled channel will be 0 to allow the roll-
over function to work smoothly.
Histogram functionality is provided for the Thermal Sensor and ADC Channel 1, and is implemented by
sampling the data and then incrementing the count value in a data bin associated with that value. The
DS1616 provides 63 2-byte data bins in 2
C increments for the temperature channel and 64 2-byte data
bins in 4-bit resolution steps (32mV/bin) for the ADC Data Channel 1. The sampling rate can be
programmed at intervals ranging from once per minute to once every 255 minutes.
The DS1616 provides programmable high- and low-temperature alarm trip points that allow the device to
monitor whether the temperature stays within desired limits. Likewise, high- and low- trip points can be
programmed for the ADC data. The device can drive an interrupt or status pin if the ADC data falls
outside of the programmable limits. The Temperature Sensor and Channel 1 of the ADC can also have
any event that falls outside of the programmed limits recorded with a time and date stamp and the
duration of the out-of-limits condition for additional analysis in the Alarm Memory. The DS1616 can be
programmed to begin sampling data via a pushbutton input or via a command sent over the serial
interface by a host machine.
A 64-bit serial number is available for unique product identification and tracking.
OVERVIEW
The block diagram in Figure 1 shows the relationship between the major control and memory sections of
the DS1616. The device has six major data components: 1) Real Time Clock and control blocks, 2)
32-byte User NV RAM with 64-bit lasered serial number, 3) 96 bytes of alarm event/duration memory, 4)
128 bytes of temperature histogram RAM, 5) 128 bytes of ADC Channel 1 data histogram RAM, and 6)
2048 bytes of datalog memory. All memory is arranged in a single linear address space.
DS1616
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DS1616 Block Diagram Figure 1
SIGNAL DESCRIPTIONS
The following paragraphs describe the function of each pin.
V
CC
- V
CC
is a +5 volt input supply. Communication with the DS1616 can take place only when V
CC
is
connected to a +5 volt supply.
V
bat
- Battery input for standard lithium cell or other energy source. All functions of the DS1616 with the
exception of the serial interface circuitry are powered by V
bat
when V
CC
< V
bat
. All functions are
powered by V
CC
when V
CC
> V
bat
. If a battery or other energy source is not used, V
bat
should be
connected directly to GND.
GND - GND connections are not internally connected, so all GND connections must be connected
directly to ground.
AGND - Analog ground should be connected directly to digital ground externally to eliminate ground
noise and potential differences.
COMSEL (Communication Select Input) - This pin determines whether serial communication is
asynchronous or synchronous. When pulled high to V
CC
, communication is synchronous and will take
place via the SCLK, I/O, and
RST
pins. When COMSEL is tied to ground, asynchronous communication
utilizing the TX and RX pins is selected. If this pin is floated, the DS1616 will operate in the
asynchronous communications mode since the COMSEL pin has a weak internal pulldown resistor.
OSCILLATOR
AND
DIVIDER
X1
X2
A/D
CONVERTER
CONTROL
LOGIC
DATALOG MEMORY
HISTOGRAM MEMORY
ALARM TIME STAMP
AND DURATION
LOGGING MEMORY
USER NVRAM
RTC AND CONTROL
REGISTERS
INTERNAL RTC
AND CONTROL
REGISTERS
SERIAL
INTERFACE
MEMORY
FUNCTION
CONTROL
Tx
Rx
ST
INSPEC
OUTSPEC
INT
COMSEL
I/O
RST
SCLK
OPTIONAL
SERIAL NUMBER
AIN
TEMPERATURE
SENSOR
3 TO 1
MUX
DS1616
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Tx (Transmit Output) - Transmit output of the asynchronous serial interface. Tx is tri-stated whenever
V
CC
< V
bat
.
Rx (Receive Input) - Receive input of the asynchronous serial interface.
SCLK (3-Wire Serial Clock Input) - The SCLK pin is the serial clock input for the 3-wire synchronous
communications channel.
I/O (3-Wire Input/Output) - The I/O pin is the data Input/Output signal for the 3-wire synchronous
communications channel.
RST
(3-Wire Reset Input) - The
RST
pin is the communications reset pin for the 3-wire synchronous
communications channel.
NT
I
(Interrupt Output) - The
INT
pin is an open drain active low output that can be connected to an
interrupt input of a microprocessor. The
INT
output remains low as long as the status bit causing the
interrupt is present and the corresponding interrupt-enable bit is set.
INSPEC
(Open Drain In-Specification Output) - This pin, in conjunction with the
OUTSPEC
pin, is
used to signal the status of the operation and data of the DS1616.
OUTSPEC
(Open Drain Out-of-Specification Output) - This pin, in conjunction with the
INSPEC
pin,
is used to signal the status of the operation and data of the DS1616.
ST
(Start/Status Button Input) - The
ST
pin provides two functions. First, when enabled as the datalog
start source (SE bit in Control 1 register is a logic 1), the
ST
pin is used to instruct the DS1616 to begin
recording data based on the programmed start delay and data sample rate. The
ST
pin must be held low
for at least 0.5 seconds for a datalog mission to begin.
Secondly, the
ST
pin can be used to poll the status of the recorded data. After datalogging has begun, the
ST
pin instructs the DS1616 to report the status of the recorded data via the
INSPEC
and
OUTSPEC
pins.
AIN1, AIN2, AIN3 (Analog Inputs) - The AINx pins are the mux'ed inputs to the ADC.
X1, X2 - Connections for a standard 32.768 kHz quartz crystal, Daiwa part number DT-26S or
equivalent. For greatest accuracy, the DS1616 must be used with a crystal that has a specified load
capacitance of 6 pF. There is no need for external capacitors or resistors. Note: X1 and X2 are very high
impedance nodes. It is recommended that they and the crystal be guard-ringed with ground and that high
frequency signals be kept away from the crystal area. For more information on crystal selection and
crystal layout considerations, please consult Application Note 58, "Crystal Considerations with Dallas
Real Time Clocks."
NC (No Connect) - These pins should be left unconnected or tied to ground.
DS1616
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MEMORY
The memory map in Figure 2a shows the general organization of the DS1616. As can be seen in the
figure, the device is segmented into 32-byte pages. Pages 0 and 1 contain the Real Time Clock and
Control registers (see Figure 2b for more detail). The User NV RAM resides in page 2. Pages 17 to 19
are assigned to storing the alarm time stamps and durations and pages 64 to 71 are reserved for histogram
memory. The data logging memory covers pages 128 to 191. Memory pages 3 to 16, 20 to 63, 68 to 127,
and 192 and up are reserved for future extensions.
The end user can write only to the Real Time Clock and Control registers and the User NV RAM. The
rest of the memory map is read-only from the end user's perspective.
DS1616 MEMORY MAP Figure 2a
0000H
to 003FH
RTC and Control Registers
pages 0 and 1
0040H
to 0005FH
User NV RAM
page 2
0060H
to 0217H
(Reserved for Future Extensions)
page 3
to page 16
(excluding last
8 bytes of
page 16)
0218H
to 021FH
Serial Number
page 16
(last 8 bytes)
00220H
to 027FH
Alarm Time Stamps and Durations
page 17
to page 19
0280H
to 07FFH
(Reserved for Future Extensions)
page 20 - 63
0800H
to 087FH
Temperature Histogram (63 Bins of 2 Bytes Each)
page 64
to page 67
0880H
to 08FFH
ADC Channel 1 Data Histogram (64 Bins of 2 Bytes Each)
page 68
to page 71
0900H
to 0FFFH
(Reserved for Future Extensions)
page 72 - 127
1000H
to 17FFH
Datalog Memory (64 pages)
page 128
to page 191
1800H
and higher
(Reserved for Future Extensions)
page 192 and
higher
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