DS1615K

DS1615K Datasheet

DS1615 16-Pin DIP DS1615S 16-Pin SOIC

Part	Datasheet
DS1615K	DS1615K (pdf)

Related Parts	Information
DS1615	DS1615
DS1615S	DS1615S
DS1615S/T&R	DS1615S/T&R

PDF Datasheet Preview
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 Y2K compatible Automatically wakes up and measures temperature at user-programmable intervals from 1 to 255 minutes Logs up to 2048 consecutive temperature measurements in read-only nonvolatile memory Records long-term temperature histogram in 63 bins with 2.0°C resolution Programmable temperature-high and temperature-low alarm 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 and tested 64-bit serial number ORDERING INFORMATION DS1615 16-Pin DIP DS1615S 16-Pin SOIC DS1615 Temperature Recorder PIN ASSIGNMENT VBAT INSPEC 5 OUTSPEC 6 INT 7 GND 8 15 COMSEL 14 RX 13 TX 12 SCLK 11 I/O 10 RST DS1615 16-Pin DIP 300 mil DS1615S 16-Pin SOIC 300 mil Top View Package Dimension Information can be found at: PIN DESCRIPTION Vbat - Battery Supply - Crystal Input - Crystal Output - No Connect INSPEC - In-specification Output OUTSPEC - Out-of-specification Output - Interrupt Output - Ground - Start/Status Input I/O SCLK TX RX COMSEL VCC - 3-wire Reset Input - 3-wire Input/Output - 3-wire Clock Input - Transmit Output - Receive Input - Communication Select - +5V Supply 1 of 24 122800 DS1615 The DS1615 is an integrated temperature recorder that combines a real time clock with temperature data logging and histogram capabilities. It has been designed for applications that require temperature profiling over a given period of time. A programmable sampling rate feature makes the device ideal for applications requiring temperature monitoring over short or long time frames. The integrated Real Time Clock RTC provides seconds, minutes, hours, day, date, month, and year information with leap year compensation 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. The DS1615 is a powerful data recording device, providing both a datalog of sampled temperature values over time and a histogram of temperature. The datalog function samples the temperature at a user defined sample rate and writes the data to the Temperature Datalog memory. Up to 2048 datalog samples may be recorded. Histogram functionality is implemented by sampling the temperature and then incrementing the count value in a data bin associated with that temperature. The DS1615 provides 63, 2-byte data bins in 2°C increments. The user can program data sampling for both data logging and for histogram tabulation at intervals ranging from once per minute to once every 255 minutes. The DS1615 also supports programmable high and low temperature alarm trip points that allow the device to monitor whether the temperature stays within desired limits. The device can drive an interrupt or status pin if the temperature falls outside of the programmable limits. The DS1615 can be programmed to begin sampling data via a pushbutton input or via a command sent over the serial interface with a host machine. The DS1615 also provides a 64-bit serial number, which is useful for product identification and tracking. OVERVIEW The block diagram in Figure 1 shows the relationship between the major control and memory sections of the DS1615. The device has five major data components 1 Real Time Clock and control block, 2 32-byte User NV RAM with 64-bit lasered serial number, 3 96 bytes of Alarm event/duration memory, 4 128 bytes of histogram RAM, and 5 2048 bytes of datalog memory. All memory is arranged in a single linear address space. 2 of 24 DS1615 BLOCK DIAGRAM Figure 1 DS1615 SIGNAL DESCRIPTIONS The DS1615 is manufactured such that no two devices will contain an identical serial number. Blocks of numbers can be reserved by the customer. Contact Dallas Semiconductor for special ordering information for devices with reserved blocks of serial numbers. SECURITY The DS1615 provides several measures to insure data integrity for the end user. These security measures are intended to prevent third party intermediaries from tampering with the data that has been stored in the Datalog and Histogram memory. As a first security measure, the Datalog and Histogram memory are Read-only from the perspective of the end user. The DS1615 can write sampled data into these memory banks, but the end user cannot write data to individual registers. This prevents an unscrupulous intermediary from writing false data to the DS1615. The end user, however, can clear the contents of the Datalog and Histogram memory. This is accomplished by enabling and issuing the Clear Memory command. 15 of 24 DS1615 A second security feature lies in the fact that once the sample rate has been selected by writing to the Sample Rate register, it cannot be changed to another value without resetting the recorded temperature data. This prevents gathering many data samples at a fast sample rate and then lowering the sample rate to give the appearance that the data was recorded over a longer period of time. The Sample Rate register can only be written to a new value if the MEM CLR bit is set to one. A third security feature lies in the two integrated sample counters - the Current Samples Counter and the Total Samples Counter. These two counters can be used to guarantee that the DS1615 data has not been cleared at any time during a given period of time. The Current Samples Counter counts the number of samples that have occurred since the most recent data acquisition operation was started i.e., the number of samples since the Sample Rate register was written to a non-zero value . The Total Samples Counter counts the total number of samples that have been recorded in the life of the device assuming the lithium energy source has not been removed during that time . If the end user knows the value in the Total Samples Counter before the data acquisition operation is started, he can guarantee that the DS1615 has not been cleared. If the Current Samples count equals the difference between the ending value and beginning value of the Total Samples Counter, then the DS1615 data has not been cleared during that time frame. As a fourth security measure, changing any value in the RTC and Control registers with the exception of the Status register will stop datalogging and clear the Mission-in-Progress MIP bit. SERIAL INTERFACE The DS1615 provides two different serial communications options asynchronous and synchronous. Both communications options will transmit the data LSb first, MSb last. The mode of communication is selected via the COMSEL pin. When this pin is pulled high, the DS1615 operates in synchronous mode. In this mode, communication with the DS1615 is facilitated by the SCLK, I/O, and RST pins. When COMSEL is pulled low or floated, asynchronous communications is selected and communication with the device occurs over the TX and RX pins. The operation of each mode is discussed in further detail below. Asynchronous Communication In asynchronous mode, the DS1615 operates as a slave peripheral device which is read and written over a half duplex asynchronous data interface at the fixed rate of 9,600 bits per second. Data is received and transmitted in 8-bit bytes using a standard asynchronous serial communications format as shown in Figure This format is easily generated by the UART in most systems. The DS1615 data format implements 10 bit words including one start bit, eight data bits, and one stop bit. Data is received by the DS1615 on the RX pin and transmitted by the TX pin. COMMUNICATION WORD FORMAT Figure 3 16 of 24 DS1615 Synchronous Communication Synchronous communication is accomplished over the 3-wire bus which is composed of three signals. These are the RST reset , the SCLK serial clock , and I/O data I/O pins. The 3-wire bus operates at a maximum data rate of 2 Mbps. All data transfers are initiated by driving the RST input high and are terminated by driving RST low. See Figures 6 and A clock cycle is a sequence of a falling edge followed by a rising edge. For data inputs, the data must be valid during the rising edge. Data bits are output on the falling edge of the clock and remain valid through the rising edge. When reading data from the DS1615, the I/O pin goes to a high impedance state when the clock is high. Taking RST low will terminate any communication and cause the I/O pin to go to a high impedance state. General Communications Format Communication with the DS1615 in both synchronous and asynchronous modes is accomplished by first writing a command to the device. The command is then followed by the parameters and/or data required by the command. The command set for the DS1615 can be seen in Table Reads and writes to the DS1615 differ in that writes are performed one byte at a time while reads are performed in page long up to 32 byte bursts. Writing one byte at a time means that a write command has to be issued before each byte of data that is written. For example, writing to the user NV RAM requires that the Write User NV RAM command be writ-ten followed by the address to be written and then the actual data byte. Writing a second data byte would require the same procedure with a new address specified. Reads, however, are accomplished in bursts. For example, if an end user wants to read data from a specific page he would first issue the Read Page command, followed by the address to begin reading. After the DS1615 receives the command and starting address, it will immediately transmit the data that resides at the given address location. However, rather than stop with that single byte of data, the DS1615 will continue transmitting the next byte of data and will continue transmitting data until the page boundary is reached. A page read can begin at any address, but will always end at the page boundary. Thus, a page read can range from 1 to 32 bytes. It should be noted that a read can be terminated at any time when communicating in synchronous mode by pulling RST to ground. However, in asynchronous mode, the DS1615 will not stop transmitting data until the page boundary is reached. Cyclical Redundancy Check CRC When communicating in the asynchronous mode, a 16-bit CRC is transmitted by the DS1615 following the transmission of all data. When communicating in synchronous mode, no CRC is transmitted. The 16-bit CRC Cyclical Redundancy Check is used to insure the accuracy of the data that is read from the DS1615. The CRC is generated according to the standardized CRC16-polynomial function X16+ X15+ X2 Figure 4 illustrates the function of the generator. The CRC is generated by clearing the CRC generator and then shifting in data from the register set being read. A sixteen bit CRC is transmitted by the DS1615 after the last register of any page of memory is read. In other words, a CRC is generated at the end boundary of every page that is read. 17 of 24 CRC HARDWARE DESCRIPTION AND POLYNOMIAL Figure 4 DS1615 Communication Reset Asynchronous Mode When transmitting the command, parameters, or data to the DS1615, it is possible that communication might be interrupted. For example, the user might accidentally disconnect the cable linking the device to the host computer. To insure that communication always starts at a known state when in the asynchronous mode, the DS1615 will reset the communication if it senses a problem. This is accomplished via two methods. First, if during the transmission of a byte of data to the DS1615, the stop bit is not received, communication will be reset. The lack of a valid stop bit indicates that particular byte of data was not received correctly. Second, if more then 10-bit times expire between the reception of one byte of data and the reception of the next required byte, then communication will be reset. Automatic resetting of communication is not required when communicating in the synchronous mode. This is because of the function of the RST pin. Pulling RST low resets the serial communication of the DS1615. DS1615 COMMANDS All communication with the DS1615 is accomplished by writing a command to the device followed by parameter byte/s if required. Table 3 illustrates the commands sup-ported by the DS1615. DS1615 COMMANDS Table 3 COMMAND FUNCTION DESCRIPTION Write Byte Write one byte to RTC, Control registers, and User NV RAM Read Page Read Page Specification Poll status of temperature extremes Test

PDF Datasheet Preview

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 Y2K compatible Automatically wakes up and measures temperature at user-programmable intervals from 1 to 255 minutes Logs up to 2048 consecutive temperature measurements in read-only nonvolatile memory Records long-term temperature histogram in 63 bins with 2.0°C resolution Programmable temperature-high and temperature-low alarm 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 and tested 64-bit serial number
ORDERING INFORMATION

DS1615 16-Pin DIP DS1615S 16-Pin SOIC

DS1615 Temperature Recorder

PIN ASSIGNMENT

VBAT

INSPEC 5

OUTSPEC 6

INT 7

GND 8
15 COMSEL
14 RX
13 TX
12 SCLK
11 I/O
10 RST

DS1615 16-Pin DIP 300 mil DS1615S 16-Pin SOIC 300 mil

Top View

Package Dimension Information can be found at:

PIN DESCRIPTION

Vbat
- Battery Supply
- Crystal Input
- Crystal Output
- No Connect

INSPEC
- In-specification Output

OUTSPEC - Out-of-specification Output
- Interrupt Output - Ground
- Start/Status Input

I/O SCLK TX RX COMSEL VCC
- 3-wire Reset Input - 3-wire Input/Output - 3-wire Clock Input - Transmit Output - Receive Input - Communication Select - +5V Supply
1 of 24
122800

DS1615

The DS1615 is an integrated temperature recorder that combines a real time clock with temperature data logging and histogram capabilities. It has been designed for applications that require temperature profiling over a given period of time. A programmable sampling rate feature makes the device ideal for applications requiring temperature monitoring over short or long time frames. The integrated Real Time Clock RTC provides seconds, minutes, hours, day, date, month, and year information with leap year compensation 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. The DS1615 is a powerful data recording device, providing both a datalog of sampled temperature values over time and a histogram of temperature. The datalog function samples the temperature at a user defined sample rate and writes the data to the Temperature Datalog memory. Up to 2048 datalog samples may be recorded. Histogram functionality is implemented by sampling the temperature and then incrementing the count value in a data bin associated with that temperature. The DS1615 provides 63, 2-byte data bins in 2°C increments. The user can program data sampling for both data logging and for histogram tabulation at intervals ranging from once per minute to once every 255 minutes. The DS1615 also supports programmable high and low temperature alarm trip points that allow the device to monitor whether the temperature stays within desired limits. The device can drive an interrupt or status pin if the temperature falls outside of the programmable limits. The DS1615 can be programmed to begin sampling data via a pushbutton input or via a command sent over the serial interface with a host machine. The DS1615 also provides a 64-bit serial number, which is useful for product identification and tracking.

OVERVIEW

The block diagram in Figure 1 shows the relationship between the major control and memory sections of the DS1615. The device has five major data components 1 Real Time Clock and control block, 2 32-byte User NV RAM with 64-bit lasered serial number, 3 96 bytes of Alarm event/duration memory, 4 128 bytes of histogram RAM, and 5 2048 bytes of datalog memory. All memory is arranged in a single linear address space.
2 of 24

DS1615 BLOCK DIAGRAM Figure 1

DS1615

SIGNAL DESCRIPTIONS
The DS1615 is manufactured such that no two devices will contain an identical serial number. Blocks of numbers can be reserved by the customer. Contact Dallas Semiconductor for special ordering information for devices with reserved blocks of serial numbers.

SECURITY

The DS1615 provides several measures to insure data integrity for the end user. These security measures are intended to prevent third party intermediaries from tampering with the data that has been stored in the Datalog and Histogram memory.

As a first security measure, the Datalog and Histogram memory are Read-only from the perspective of the end user. The DS1615 can write sampled data into these memory banks, but the end user cannot write data to individual registers. This prevents an unscrupulous intermediary from writing false data to the DS1615. The end user, however, can clear the contents of the Datalog and Histogram memory. This is accomplished by enabling and issuing the Clear Memory command.
15 of 24

DS1615

A second security feature lies in the fact that once the sample rate has been selected by writing to the Sample Rate register, it cannot be changed to another value without resetting the recorded temperature data. This prevents gathering many data samples at a fast sample rate and then lowering the sample rate to give the appearance that the data was recorded over a longer period of time. The Sample Rate register can only be written to a new value if the MEM CLR bit is set to one.

A third security feature lies in the two integrated sample counters - the Current Samples Counter and the Total Samples Counter. These two counters can be used to guarantee that the DS1615 data has not been cleared at any time during a given period of time. The Current Samples Counter counts the number of samples that have occurred since the most recent data acquisition operation was started i.e., the number of samples since the Sample Rate register was written to a non-zero value . The Total Samples Counter counts the total number of samples that have been recorded in the life of the device assuming the lithium energy source has not been removed during that time . If the end user knows the value in the Total Samples Counter before the data acquisition operation is started, he can guarantee that the DS1615 has not been cleared. If the Current Samples count equals the difference between the ending value and beginning value of the Total Samples Counter, then the DS1615 data has not been cleared during that time frame.

As a fourth security measure, changing any value in the RTC and Control registers with the exception of the Status register will stop datalogging and clear the Mission-in-Progress MIP bit.

SERIAL INTERFACE

The DS1615 provides two different serial communications options asynchronous and synchronous. Both communications options will transmit the data LSb first, MSb last.

The mode of communication is selected via the COMSEL pin. When this pin is pulled high, the DS1615 operates in synchronous mode. In this mode, communication with the DS1615 is facilitated by the SCLK, I/O, and RST pins. When COMSEL is pulled low or floated, asynchronous communications is selected and communication with the device occurs over the TX and RX pins. The operation of each mode is discussed in further detail below.

Asynchronous Communication

In asynchronous mode, the DS1615 operates as a slave peripheral device which is read and written over a half duplex asynchronous data interface at the fixed rate of 9,600 bits per second. Data is received and transmitted in 8-bit bytes using a standard asynchronous serial communications format as shown in Figure This format is easily generated by the UART in most systems. The DS1615 data format implements 10 bit words including one start bit, eight data bits, and one stop bit. Data is received by the DS1615 on the RX pin and transmitted by the TX pin.

COMMUNICATION WORD FORMAT Figure 3
16 of 24

DS1615

Synchronous Communication

Synchronous communication is accomplished over the 3-wire bus which is composed of three signals. These are the RST reset , the SCLK serial clock , and I/O data I/O pins. The 3-wire bus operates at a maximum data rate of 2 Mbps. All data transfers are initiated by driving the RST input high and are terminated by driving RST low. See Figures 6 and A clock cycle is a sequence of a falling edge followed by a rising edge. For data inputs, the data must be valid during the rising edge. Data bits are output on the falling edge of the clock and remain valid through the rising edge.

When reading data from the DS1615, the I/O pin goes to a high impedance state when the clock is high. Taking RST low will terminate any communication and cause the I/O pin to go to a high impedance state.

General Communications Format

Communication with the DS1615 in both synchronous and asynchronous modes is accomplished by first writing a command to the device. The command is then followed by the parameters and/or data required by the command. The command set for the DS1615 can be seen in Table Reads and writes to the DS1615 differ in that writes are performed one byte at a time while reads are performed in page long up to 32 byte bursts. Writing one byte at a time means that a write command has to be issued before each byte of data that is written. For example, writing to the user NV RAM requires that the Write User NV RAM command be writ-ten followed by the address to be written and then the actual data byte. Writing a second data byte would require the same procedure with a new address specified. Reads, however, are accomplished in bursts. For example, if an end user wants to read data from a specific page he would first issue the Read Page command, followed by the address to begin reading. After the DS1615 receives the command and starting address, it will immediately transmit the data that resides at the given address location. However, rather than stop with that single byte of data, the DS1615 will continue transmitting the next byte of data and will continue transmitting data until the page boundary is reached. A page read can begin at any address, but will always end at the page boundary. Thus, a page read can range from 1 to 32 bytes. It should be noted that a read can be terminated at any time when communicating in synchronous mode by pulling RST to ground. However, in asynchronous mode, the DS1615 will not stop transmitting data until the page boundary is reached.

Cyclical Redundancy Check CRC

When communicating in the asynchronous mode, a 16-bit CRC is transmitted by the DS1615 following the transmission of all data. When communicating in synchronous mode, no CRC is transmitted.

The 16-bit CRC Cyclical Redundancy Check is used to insure the accuracy of the data that is read from the DS1615. The CRC is generated according to the standardized CRC16-polynomial function X16+ X15+ X2 Figure 4 illustrates the function of the generator. The CRC is generated by clearing the CRC generator and then shifting in data from the register set being read. A sixteen bit CRC is transmitted by the DS1615 after the last register of any page of memory is read. In other words, a CRC is generated at the end boundary of every page that is read.
17 of 24

CRC HARDWARE DESCRIPTION AND POLYNOMIAL Figure 4

DS1615

Communication Reset Asynchronous Mode

When transmitting the command, parameters, or data to the DS1615, it is possible that communication might be interrupted. For example, the user might accidentally disconnect the cable linking the device to the host computer. To insure that communication always starts at a known state when in the asynchronous mode, the DS1615 will reset the communication if it senses a problem. This is accomplished via two methods. First, if during the transmission of a byte of data to the DS1615, the stop bit is not received, communication will be reset. The lack of a valid stop bit indicates that particular byte of data was not received correctly. Second, if more then 10-bit times expire between the reception of one byte of data and the reception of the next required byte, then communication will be reset.

Automatic resetting of communication is not required when communicating in the synchronous mode.

This is because of the function of the RST pin. Pulling RST low resets the serial communication of the DS1615.

DS1615 COMMANDS

All communication with the DS1615 is accomplished by writing a command to the device followed by
parameter byte/s if required. Table 3 illustrates the commands sup-ported by the DS1615.

DS1615 COMMANDS Table 3

COMMAND FUNCTION DESCRIPTION

Write Byte Write one byte to RTC, Control registers, and User NV RAM

Read Page Read Page

Specification Poll status of temperature extremes

Test

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Datasheet ID: DS1615K 508385