DS2404S Dallas Semiconductor, DS2404S Datasheet
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DS2404S
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DS2404S Summary of contents
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... Operating voltage range from 2.8 to 5.5 Volts ORDERING INFORMATION DS2404 16-pin DIP DS2404S 16-pin SOIC DS2404B 16-pin SSOP DESCRIPTION The DS2404 EconoRAM Time Chip offers a simple solution for storing and retrieving vital data and time information with minimal hardware. The DS2404 contains a unique lasered ROM, real-time clock/calendar, interval timer, cycle counter, programmable interrupts and 4096-bits of SRAM ...
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DETAILED PIN DESCRIPTION PIN SYMBOL 1, IRQ 3 RST I/O 6 CLK 7,12 NC 8,13 GND 9 V BATB 10 V BATO 11 1Hz 14, OVERVIEW The DS2404 has four ...
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The “Power Control” section provides for two basic power configurations, battery operate mode and V operate mode. The battery operate mode utilizes one supply connected to V may utilize two supplies; the primary supply connects to V DS2404 BLOCK DIAGRAM ...
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... Figure 3. The polynomial is X Wire Cyclic Redundancy Check is available in Application Note 27, “Understanding and Using Cyclic Redundancy Checks with Dallas Semiconductor iButton Products”. The shift register bits are initialized to zero. Then starting with the least significant bit of the family code, one bit at a time is shifted in ...
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MEMORY MAP Figure DS2404 020998 ...
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MEMORY The memory map in Figure 4 shows a page (32 bytes) called the scratchpad and 17 pages called memory. Pages 0 through 15 each contain 32 bytes which make up the 4096-bit SRAM. Page 16 has only 30 bytes ...
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Alarm Registers The alarm registers for the real-time clock, interval timer, and cycle counter all operate in the same manner. When the value of a given counter equals the value in its associated alarm register, the appropriate flag bit is ...
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Setting a write protect bit to a logic 1 will permanently write protect the corresponding counter and alarm registers, all write protect bits, and additional bits in the control register. The write protect bits can not be written in a ...
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The third register (E/ read only register. The first five bits (E4: E0) of this register are called the ending offset. The ending offset is a byte offset within a page. Bit 5 (PF) is the partial byte ...
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MEMORY FUNCTION FLOW CHART Figure DS2404 020998 ...
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Read Memory [F0h] The read memory command may be used to read the entire memory. After issuing the command, the user must provide the 2-byte target address. After the two bytes, the user reads data beginning from the target address ...
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Example 2: Write two data bytes to memory locations 0026h and 0027h (the seventh and eighth byte of page 1). Read entire memory (1-Wire port). MASTER MODE DATA(LSB FIRST ...
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The write protect bits, once set, permanently write protects their corresponding counter and alarm registers, all write protect bits, and certain control register bits as shown in Figure 7. The time/count registers will continue to count if the oscillator is ...
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HARDWARE CONFIGURATION Figure 8 TRANSACTION SEQUENCE The protocol for accessing the DS2404 via the 1-Wire port is as follows: § Initialization § ROM Function Command § Memory Function Command § Transaction/Data INITIALIZATION All transactions on the 1-Wire bus begin with ...
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Skip ROM [CCh] This command can save time in a single drop bus system by allowing the bus master to access the memory functions without providing the 64-bit ROM code. If more than one slave is present on the bus ...
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ROM FUNCTIONS FLOW CHART (1-WIRE PORT ONLY) Figure 9 (See Figure DS2404 020998 ...
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SIGNALING The DS2404 requires strict protocols to ensure data integrity. The protocol consists of five types of signaling on one line: Reset Sequence with reset pulse and presence pulse, write 0, write 1, Read Data and interrupt pulse. All ...
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READ/WRITE TIMING DIAGRAM Figure 11 Write-one Time Slot Write-zero Time Slot Read-data Time Slot RESISTOR MASTER DS2404 60 s < t < 120 s SLOT < LOW1 < REC ...
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Interrupts If the DS2404 detects an alarm condition, it will automatically set the corresponding alarm flag (CCF, ITF or RTF) in the Status Register. If the flag’ s corresponding interrupt bit ( (logic 0) an interrupt condition begins as the ...
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TYPE 1 INTERRUPT Figure 12 TYPE 1A INTERRUPT (SPECIAL CASE) Figure 13 TYPE 2 INTERRUPT Figure 14 DS2404 DS2404 020998 ...
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TYPE 2 INTERRUPT (SPECIAL CASE) Figure 15 3-WIRE I/O COMMUNICATIONS The 3–wire bus is comprised of three signals. These are the and the DQ (data) signal. All data transfers are initiated by driving the input low terminates communication. (See Figures ...
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V Operate Mode (Battery Backed) CC Figure 16 shows the necessary connections for operating the DS2404 in V VCC OPERATE MODE Figure BATB V BATO To always allow communication through the 1-Wire or wire port, the ...
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Battery Operate Mode Figure 17 shows the necessary connections for operating the DS2404 in Battery Operate mode. BATTERY OPERATE MODE Figure BATB V BATO The V pin is normally connected to any standard 3 V lithium ...
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DUAL PORT OPERATION The on-chip arbitration logic works on a first-come, first serve principle. Assuming that at one time both ports are idle, the one port that becomes active prior to the other one is granted access. Activity on the ...
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CRYSTAL PLACEMENT ON PCB Figure 18 3-WIRE WRITE DATA TIMING DIAGRAM Figure 19 3-WIRE READ DATA TIMING DIAGRAM Figure DS2404 020998 ...
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ABSOLUTE MAXIMUM RATINGS* Voltage on DATA to Ground Operating Temperature Storage Temperature Soldering Temperature This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of ...
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CAPACITANCE PARAMETER Input Capacitance Output Capacitance I/O (1-Wire) RESISTANCES PARAMETER Resistance to Ground RST DQ Resistance to Ground CLK Resistance to Ground AC ELECTRICAL CHARACTERISTICS: 3-WIRE PORT PARAMETER Data to CLK Setup CLK to Data Hold CLK to Data Delay ...
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NOTES: 1. All voltages are referenced to ground 2. 0.8V with 10 ns maximum rise and fall time 2.4V and V = 0.4V, respectively. DQH DQL 4. Load capacitance ...