DS1615 Maxim Integrated Products, DS1615 Datasheet
DS1615
Specifications of DS1615
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DS1615 Summary of contents
Page 1
... SCLK 6 11 I/O INT 7 10 RST GND DS1615 16-Pin DIP (300 mil) DS1615S 16-Pin SOIC (300 mil) Top View - Battery Supply - Crystal Input - Crystal Output - No Connect - In-specification Output - Out-of-specification Output - Interrupt Output - Ground - Start/Status Input - 3-wire Reset Input - 3-wire Input/Output - 3-wire Clock Input ...
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... 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 ...
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... When pulled high to V place via the SCLK, I/O, and utilizing the TX and RX pins is selected. If this pin is floated, the DS1615 will operate in the asynchronous communications mode since the COMSEL pin has a weak internal pulldown resistor. Tx (Transmit Output) - Transmit output of the asynchronous serial interface tri-stated whenever V < ...
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... NC (No Connect) - This pin should be left unconnected. MEMORY The memory map in Figure 2a shows the general organization of the DS1615. 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 are assigned to storing the alarm time stamps and durations ...
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... DS1615 MEMORY MAP Figure 2a Address 0000H RTC AND CONTROL REGISTERS 001FH 0020H 003FH 0040H 005FH 0060H (RESERVED FOR FUTURE EXTENSIONS) 0217H 0218H 021FH 0220H ALARM TIME STAMPS AND DURATIONS 027FH 0280H (RESERVED FOR FUTURE EXTENSIONS) 07FFH 0800H TEMPERATURE HISTOGRAM (63 BINS OF 2 BYTES EACH) ...
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... DS1615 RTC AND CONTROL PAGE Figure 2b ADDRESS BIT 7 BIT 12/ Years Seconds Alarm Minutes Alarm 09 MH 12/ Number Of Minutes Between Temperature Conversions 0E CLR EOSC MEM CLR 20-3F BIT 5 BIT 4 BIT 3 10 Seconds 10 Minutes A Date Single Seconds Alarm Single Minutes Alarm alm A Low Temperature Threshold ...
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... DS1615 ALARM TIME STAMPS AND DURATIONS Figure 2c Sample Counter Address (Low, Medium, High Bytes) 220, 221, 222 224, 225, 226 228, 229, 22A 22C, 22D, 22E 230, 231, 232 234, 235, 236 238, 239, 23A 23C, 23D, 23E 240, 241, 242 ...
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... Read Temperature command is issued and is set to a logic 1 upon the completion of the conversion. DATA LOGGING When the DS1615 datalogging function is enabled, the device is said datalog mission until the data-logging is stopped. During a datalog mission, temperature samples are successively written to the Temperature Datalog memory pages ...
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... As a safety measure, the DS1615 has been designed such that the end user cannot write to the Temperature Datalog Memory. This prevents the falsification of data-log data by writing values to datalog registers ...
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... The user can set a high and a low temperature threshold. As long as the temperature samples stay within this tolerance band (i.e., are higher than the low threshold and lower than the high threshold), the DS1615 will not record any temperature alarm. If the temperature violates the temperature band, the DS1615 will generate an alarm and set either the Temperature High Flag (THF) or the Temperature Low Flag (TLF) in the Status register (address 0014h) ...
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... Binary-Coded Decimal (BCD) format. The DS1615 can run in either 12-hour or 24-hour mode. Bit 6 of the hours register is defined as the 12- 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 one being PM ...
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... Enable oscillator - This bit controls the state of the oscillator in battery back-up mode only. EOSC When set to logic 0, the oscillator is active. When this bit is set to a logic 1, the oscillator is stopped and the DS1615 is placed into a low-power standby mode with a current drain of less than 100 nanoamps at room temperature. When V CC this bit ...
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... MEM CLR is cleared to 0 when a datalog mission is started (i.e., MIP = 1). MIP - Mission in Progress This bit indicates the sampling status of the DS1615. If MIP is a logic 1, the device is currently on a mission in which it is operating in the datalogging mode. The MIP bit is changed to a logic 1 immediately following 1) the writing of a non-zero value to the Sample Rate register when the SE bit ...
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... SR7 SR6 The data sample rate for the DS1615 can range from once per minute to once per 255 minutes. The rate is equal to the value written to the Sample Rate register multiplied by one minute. This register can only be written to a new value when the MEM CLR bit in the Status register is set to 1. ...
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... 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 ...
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... 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 3 ...
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... 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. ...
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... DS1615 will reset the communication if it senses a problem. 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 that particular byte of data was not received correctly ...
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... In synchronous mode, the DS1615 will continue to transmit data as long as clocks are presented to the serial interface. If clocks are presented after the final data bit of the last register in the page, the DS1615 will wrap-around to the first register in the page and sequentially transmit data as long as the clocks continue. ...
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... CLR bit in the Control register to a one. After clearing the memory, the MEM CLR bit in the Status register is set. The Clear Memory command functions only if the oscillator is active. The DS1615 is inaccessible for 500 µ s after the Clear Memory command has been issued. D5 ...
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... Output INSPEC OUTSPEC Current @ 0.8V Active Supply Current Temperature Conversion Current Oscillator Current Battery Standby Current (Oscillator Off) DS1615 Thermometer Error CAPACITANCE PARAMETER Input Capacitance Crystal Capacitance -0.3V to +7.0V -40 ° +85 ° C -55 ° +125 ° C See J-STD-020A specification SYMBOL MIN ...
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AC ELECTRICAL CHARACTERISTICS PARAMETER Vcc rise/fall time Delay from INSPEC Active OUTSPEC Delay from Specification to or Active INSPEC OUTSPEC Temperature Conversion Time and Active INSPEC OUTSPEC Low Pulse Width and High INSPEC OUTSPEC Duration ASYNCHRONOUS INTERFACE ...
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POWER-UP/DOWN WAVEFORM TIMING Figure 5 Vcc t F ASYNCHRONOUS SERIAL INTERFACE TIMING Figure 5 SYNCHRONOUS (3-WIRE) SERIAL INTERFACE READ TIMING Figure 6 SYNCHRONOUS (3-WIRE) SERIAL INTERFACE WRITE TIMING Figure 7 4.75V 0.25V ...
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SPECIFICATION POLLING FROM ST INPUT Figure 8 ST INSPEC OUTSPEC SPECIFICATION POLLING FROM COMMAND Figure 9 RX start data = 55h INSPEC OUTSPEC stop ...