DS2482-100 Dallas Semiconducotr, DS2482-100 Datasheet
DS2482-100
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DS2482-100 Summary of contents
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... GENERAL DESCRIPTION The DS2482-100 is an I²Cä to 1-Wire that interfaces directly to standard (100kHz max) or fast (400kHz max) I²C masters to perform bi- directional protocol conversion between the I²C master and any downstream 1-Wire slave devices. Relative to any attached 1-Wire slave device, the DS2482-100 is a 1-Wire master ...
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ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground Maximum Current into Any Pin Operating Temperature Range Junction Temperature Storage Temperature Range Soldering Temperature Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the ...
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PARAMETER Write-0 Low Time Write-0 Recovery Time Reset Low Time Presence Detect Sample Time Sampling for Short and Interrupt Reset High Time Presence-Pulse Mask Start Presence-Pulse Mask Stop Control Pin (PCTLZ) Output-Low Voltage Output-High Voltage I²C Pins (Note 9) See ...
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... Applies to SDA, SCL, and AD0, AD1. Note 11: I/O pins of the DS2482 do not obstruct the SDA and SCL lines if V Note 12: The DS2482 provides a hold time of at least 300ns for the SDA signal (referred to the V undefined region of the falling edge of SCL. Note 13: The maximum t ...
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... AD1 DETAILED DESCRIPTION The DS2482-100 is a self-timed 1-Wire master, which supports advanced 1-Wire waveform features including standard and Overdrive speeds, active pullup, strong pullup for power delivery, and presence-pulse masking. Once supplied with command and data, the I/O controller of the DS2482 performs time-critical 1-Wire communication functions such as reset/presence detect cycle, read-byte, write-byte, single-bit R/W and triplet for ROM Search, without requiring interaction with the host processor ...
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... The active pullup does not apply to the rising edge of a presence pulse or a recovery after a short on the 1-Wire line. The circuit that controls rising edges (Figure 2) operates as follows the pulldown (from DS2482 or 1-Wire slave) ends. From this point on the 1-Wire bus is pulled high through R capacitive load of the 1-Wire line determine the slope ...
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... If SPU is 1, the DS2482 applies active pullup to the rising edge of the time slot in which the strong pullup starts, regardless of the APU bit setting. However, in contrast to setting APU = 1 for active pullup, the low-impedance ...
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... Reset command. Short Detected (SD) The SD bit is updated with every 1-Wire Reset command. If the DS2482 detects a logic 0 on the 1-Wire line at t during the Presence Detect cycle, the SD bit is set to 1. This bit returns to its default 0 with a subsequent 1-Wire Reset command provided that the short has been removed ...
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... FUNCTION COMMANDS The DS2482 understands eight function commands, which fall into four categories: device control, I²C communication, 1-Wire set-up and 1-Wire communication. The feedback path to the host is controlled by a read pointer, which is set automatically by each function command for the host to efficiently access relevant information. ...
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... Status register, bits PPD and SD. To initiate or end any 1-Wire communication sequence. 1-Wire activity must have ended before the DS2482 can process this command. Command code is not acknowledged if 1WB = 1 at the time the command code is received and the command is ignored. ...
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... To perform single bit writes or reads at the 1-Wire line when single bit communication is necessary (the exception). 1-Wire activity must have ended before the DS2482 can process this command. Command code and bit byte are not acknowledged if 1WB = 1 at the time the command code is received and the command is ignored ...
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... NOTE on Figure 7: Depending on its internal state, a 1-Wire slave device transmits data to its master (e.g., the DS2482). When responding with 1-Wire slave starts pulling the line low during t generator determines when this pulldown ends and the voltage starts rising again. When responding with ...
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... The direction byte determines the type of write time slot if both read time slots are 0 (a typical case). In this case the DS2482 generates a write 1- time slot and a write-0 time slot the read time slots are 0 and 1, there follows a write-0 time slot. ...
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... Condition Slave Address The slave address to which the DS2482 responds is shown in Figure 9. The logic states at the address pins AD0 and AD1 determine the value of the address bits A0 and A1. The address pins allow the device to respond to one of four possible slave addresses. The slave address is part of the slave-address/control byte. The last bit of the slave-address/control byte ( defines the data direction. When set subsequent data flows from master to slave (write access) ...
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I²C Definitions The following terminology is commonly used to describe I²C data transfers. The timing references are defined in Figure 10. Figure 10. I²C Timing Diagram SDA t BUF t LOW SCL t t HD:STA R STOP START NOTE: Timing ...
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... SDA, allowing the master to generate the STOP condition. Writing to the DS2482 To write to the DS2482, the master must access the device in write mode, i.e., the slave address must be sent with the direction bit set to 0. The next byte to be sent is a command code, which, depending on the command, may be followed by a command parameter ...
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... In the first cycle, the master sends the command; then the master waits (Idle) for the 1-Wire Reset to complete. In the second cycle the DS2482 is accessed to read the result of the 1-Wire Reset from the Status register. Case B: 1-Wire Idle (1WB = 0), Busy Polling Until the 1-Wire Command is Completed, then Read the Result ...
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... E1h) and access the device again to read the data byte that was obtained from the 1-Wire line. Case D: 1-Wire Busy (1WB = 1) S AD,0 A 1WRB The master should stop and restart as soon as the DS2482 does not acknowledge the command code. A 33h A P (Idle) ...
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... When 1WB has changed from the Status register holds the valid result of the 1-Wire Triplet command. Case C: 1-Wire Busy (1WB = 1) S AD,0 A 1WT The master should stop and restart as soon as the DS2482 does not acknowledge the command code. A <byte> (Idle) ...
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... AD1 Line termination resistor, typically 100 I²C pull-up resistor, see Application P Information for R SDA PCTLZ SCL DS2482-100 AD0 *R 1-Wire line t AD1 Current Limiting Resistor 1-Wire line 1-Wire Device #1 (with special power requirements) sizing. ...
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Since a 885W pullup resistor, as would be required to meet the rise time specification at fast speed and 400pF bus capacitance, is lower than Rpmin at 5.5V, a different approach is necessary. The "Max. Load…" line in Figure 12 ...