TOP VIEW CLOCK GENERATOR A1 A2 GND CPU SPEED SELECT

Similar documents
2-Wire, 5-Bit DAC with Three Digital Outputs

PART IN+ IN- TX_DISABLE TX_FAULT BIAS SET BIASMAX 2 APCSET 2 MODSET 2 MOD SET PC_MON BS_MON

DS WIRE INTERFACE 11 DECOUPLING CAP GND

Temperature-Controlled, NV, I2C, Logarithmic Resistor DS1841

High-Voltage, NV, I2C POT with Temp Sensor and Lookup Table

DS1845 Dual NV Potentiometer and Memory

DS1855 Dual Nonvolatile Digital Potentiometer and Secure Memory

Digital Thermometer and Thermostat

DS1682 Total-Elapsed-Time Recorder with Alarm

DS28CM00. I²C/SMBus Silicon Serial Number

DS1846 NV Tri-Potentiometer, Memory, and MicroMonitor

DS75 Digital Thermometer and Thermostat

ORDERING INFORMATION. OPERATION Measuring Temperature A block diagram of the DS1621 is shown in Figure 1. DESCRIPTION ORDERING PACKAGE

Digital Thermometer and Thermostat

DS1631/DS1631A/DS1731 High-Precision Digital Thermometer and Thermostat

Gamma or VCOM Channel Functional Diagram LATCH A MUX EEPROM ADDRESS

Total-Elapsed-Time and Event Recorder with Alarm

Digital Thermometer and Thermostat

DS1232 MicroMonitor Chip

DS1625. Digital Thermometer and Thermostat FEATURES PIN ASSIGNMENT

12 Push-Pull Outputs and 4 Inputs

DS1626/DS1726 High-Precision 3-Wire Digital Thermometer and Thermostat

and 8 Open-Drain I/Os

+Denotes a lead(pb)-free/rohs-compliant package.

FM24CL04 4Kb FRAM Serial Memory

DS1624 Digital Thermometer and Memory

DS21S07AE. SCSI Terminator

Digital Thermometer and Thermostat in SOT23

DS Wire Digital Thermometer and Thermostat

PCA bit multiplexed/1-bit latched 6-bit I 2 C EEPROM DIP switch

I 2 C Port Expander with Eight Inputs. Features

Fremont Micro Devices, Inc.

PI4IOE5V bit general purpose outputs for 1MHz I 2 C bus

Features. Ordering Information. Selector Guide. Applications. Pin Configurations. I 2 C Port Expander with 8 Open-Drain I/Os

FM24C16C-GTR. 16Kb Serial 5V F-RAM Memory. Features. Description. Pin Configuration NC NC NC VSS VDD WP SCL SDA. Ordering Information.

12-Bit Plus Sign Temperature Sensors with SMBus/I2C-Compatible Serial Interface

ABRIDGED DATA SHEET. DeepCover Secure Authenticator. Benefits and Features. General Description. Applications

FM24C16B-GTR. 16Kb Serial 5V F-RAM Memory. Features. Pin Configuration. Description. Ordering Information NC NC NC VSS VDD WP SCL SDA.

FXL6408 Fully Configurable 8-Bit I 2 C-Controlled GPIO Expander

DS1834/A/D Dual EconoReset with Pushbutton

DS2405. Addressable Switch PIN ASSIGNMENT

Digital Temperature Sensors and Thermal Watchdog with Bus Lockup Protection

DS2430A 256-Bit 1-Wire EEPROM

DALLAS DS1816. Econo Reset BOTTOM VIEW TO-92 PACKAGE. See Mech. Drawings Section On Website SOT-23

DS1345W 3.3V 1024k Nonvolatile SRAM with Battery Monitor

GT24C02. 2-Wire. 2Kb Serial EEPROM (Smart Card application)

GT34C02. 2Kb SPD EEPROM

24C08/24C16. Two-Wire Serial EEPROM. Preliminary datasheet 8K (1024 X 8)/16K (2048 X 8) General Description. Pin Configuration

DS3911 Temperature-Controlled, Nonvolatile, I2C Quad DAC

ACE24AC128 Two-wire Serial EEPROM

FM24C02A 2-Wire Serial EEPROM

DS2465 DeepCover Secure Authenticator with SHA-256 Coprocessor and 1-Wire Master Function. R P = 1.1kΩ MAXIMUM I 2 C BUS CAPACITANCE 320pF V CC

ACE24AC64 Two-wire Serial EEPROM

PCA9560 Dual 5-bit multiplexed 1-bit latched I 2 C EEPROM DIP switch

DS1821 Programmable Digital Thermostat and Thermometer

N U M B ER O F V L V C C T R A N SL A T O R S

FM24C Kb FRAM Serial Memory Features

Digital Thermometers and Thermostats with SPI/3-Wire Interface

ACE24AC02A1 Two-wire Serial EEPROM

PI4IOE5V9675. Remote 16-bit I/O expander for Fm+ I 2 C-bus with interrupt Description. Features. Pin Configuration

DS2223/DS2224. EconoRAM FEATURES PACKAGE OUTLINE. PIN CONNECTIONS Pin 1 GND Ground Pin 2 DQ Data In/Out Pin 3 V CC Supply Pin 4 GND Ground

GT24C256 2-WIRE. 256K Bits. Serial EEPROM

DS2401 Silicon Serial Number

PI4IOE5V bit I 2 C-bus and SMBus I/O port with reset. Description. Features. Pin Configuration

ACE24C512C Two-wire serial EEPROM

FM24C02B/04B/08B/16B 2-Wire Serial EEPROM

GT24C WIRE. 1024K Bits. Serial EEPROM

9-Bit/12-Bit Temperature Sensors with I 2 C-Compatible Serial Interface in a SOT23

FM24C Kb FRAM Serial Memory Features

DS1852 Optical Transceiver Diagnostic Monitor

Digital Temperature Sensors and Thermal Watchdog with Bus Lockup Protection

DS1821 Programmable Digital Thermostat and Thermometer

DS1676 Total Elapsed Time Recorder, Erasable

Remote 16-bit I/O expander for Fm+ I 2 C-bus with interrupt and reset. Description

ACE24AC16B Two-wire Serial EEPROM

FM24C64C-GTR. 64Kb Serial 5V F-RAM Memory Features. Pin Configuration. Description A0 A1 A2 VSS VDD SCL SDA. Ordering Information.

INTEGRATED CIRCUITS. PCA bit I 2 C and SMBus I/O port with interrupt. Product data sheet Supersedes data of 2004 Jul 27.

INTEGRATED CIRCUITS. PCA bit I 2 C and SMBus I/0 port with reset. Product data Supersedes data of 2002 May Dec 13

PI4IOE5V bit I 2 C-bus and SMBus low power I/O port with interrupt and reset

DS2401 Silicon Serial Number

Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface

DS 1682 Total Elapsed Time Recorder with Alarm

DS1673 Portable System Controller

DS1243Y 64K NV SRAM with Phantom Clock

DS1306. Serial Alarm Real Time Clock (RTC)

DS1306 Serial Alarm Real-Time Clock

DS1217M Nonvolatile Read/Write Cartridge

ACE24AC02A3C Two-wire Serial EEPROM

EEPROM-Programmable, Hex/Quad, Power-Supply Sequencers/Supervisors

1-Cell/2-Cell Fuel Gauge with ModelGauge

PART TOP VIEW. TO LOAD SINGLE Li+ CELL TO IN LOGIC OUT. Maxim Integrated Products 1

FM24C1024A. Apr Data Sheet. Data Sheet FM24C1024A 2-wrie Serial EEPROM Ver 1.1 1

DS2484 Single-Channel 1-Wire Master with Adjustable Timing and Sleep Mode

GT24C32A 2-WIRE. 32K Bits. Serial EEPROM

DP7140. Single Channel 256 Tap DP with Integrated EEPROM and I 2 C Control. The DP7140 is a single channel non-volatile digital

DS1249Y/AB 2048k Nonvolatile SRAM

GT24C64 2-WIRE. 64K Bits. Serial EEPROM

Preliminary Data MOS IC. Type Ordering Code Package SDA Q67100-H5092 P-DIP-8-1

LM75A Digital temperature sensor and thermal watchdog

2-wire Serial EEPROM AT24C512. Preliminary. 2-Wire Serial EEPROM 512K (65,536 x 8) Features. Description. Pin Configurations.

Transcription:

Rev 0; 6/04 9-Bit I 2 C Nonvolatile General Description The is a 9-bit nonvolatile (NV) I/O expander with 64 bytes of NV user memory controlled by an I 2 C TM - compatible serial interface. The offers users a digitally programmable alternative to hardware jumpers and mechanical switches that are being used to control digital logic nodes. Furthermore, the digital state of each pin can be read through the serial interface. Each I/O pin is independently configurable. The outputs are open drain with selectable pullups. Each output has the ability to sink up to 12mA. Since the device is NV, it powers up in the desired state allowing it to control digital logic inputs immediately on power-up without having to wait for the host CPU to initiate control. Applications RAM-Based FPGA Bank Switching for Multiple Profiles Selecting Between Boot Flash Setting ASIC Configurations/Profiles Servers Network Storage Routers Telecom Equipment PC Peripherals Typical Operating Circuit Features Programmable Replacement for Mechanical Jumpers and Switches Nine NV Input/Output Pins 64-Byte NV User Memory (EEPROM) I 2 C-Compatible Serial Interface Up to 8 Devices Can be Multidropped on the Same I 2 C Bus Open-Drain Outputs with Configurable Pullups Outputs Capable of Sinking 12mA Low Power Consumption Wide Operating Voltage (2.7V to 5.5V) Operating Temperature Range: -40 C to +85 C Add /T&R for tape and reel orders. Ordering Information PART TEMP RANGE PIN-PAGE E -40 C to +85 C 16 TSSOP Pin Configuration TOP VIEW 0.1µF FROM SYSTEM CONTROLLER 4.7kΩ 4.7kΩ SCL SDA A0 I/O_0 I/O_1 I/O_2 I/O_3 I/O_4 I/O_5 FPGA CLOCK GENERATOR I/O_0 I/O_1 I/O_2 I/O_3 I/O_4 A0 1 2 3 4 5 6 16 15 14 13 12 11 GND I/O_8 I/O_7 I/O_6 I/O_5 A2 A1 A2 GND I/O_6 I/O_7 I/O_8 CPU SPEED SELECT A1 7 8 10 9 SCL SDA I 2 C is a trademark of Philips Corp. Purchase of I 2 C components from Maxim Integrated Products, Inc., or one of its sublicensed Associated Companies, conveys a license under the Philips I 2 C Patent Rights to use these components in an I 2 C system, provided that the system conforms to the I 2 C Standard Specification as defined by Philips. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim s website at www.maxim-ic.com.

ABSOLUTE MAXIMUM RATINGS Voltage on, SDA, and SCL Pins Relative to Ground...-0.5V to +6.0V Voltage on A0, A1, A2, and I/O_n [n = 0 to 8] Relative to Ground...-0.5V to ( + 0.5V) not to exceed +6.0V Operating Temperature Range...-40 C to +85 C EEPROM Programming Temperature Range...0 C to +70 C Storage Temperature Range...-55 C to +125 C Soldering Temperature...See IPC/JEDEC J-STD-020A Specification Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED DC OPERATING CONDITIONS (T A = -40 C to +85 C) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage (Note 1) +2.7 +5.5 V Input Logic 1 V IH 0.7 x + 0.3 V Input Logic 0 V IL -0.3 0.3 x V DC ELECTRICAL CHARACTERISTICS ( = +2.7V to +5.5V; T A = -40 C to +85 C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Standby Current I STBY (Note 2) 2 10 µa Input Leakage I L -1.0 +1.0 µa Input Current each I/O Pin I I/O 0.4V < V I/O < 0.9 (Note 3) -1.0 +1.0 µa 3mA sink current 0 0.4 Low-Level Output Voltage (SDA) V OL SDA 6mA sink current 0 0.6 V I/O Pin Low-Level Output Voltage V OL I/O 12mA sink current 0.4 V I/O Pin Pullup Resistors R PU 4.0 5.5 7.5 kω I/O Capacitance C I/O (Note 4) 10 pf Power-On Reset Voltage V POR 1.6 V 2

AC ELECTRICAL CHARACTERISTICS (See Figure 2) ( = +2.7V to +5.5V; T A = -40 C to +85 C, unless otherwise noted. Timing referenced to V IL(MAX) and V IH(MIN).) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SCL Clock Frequency f SCL (Note 5) 0 400 khz Bus Free Time Between Stop and Start Conditions Hold Time (Repeated) Start Condition t BUF 1.3 µs t HD:STA 0.6 µs Low Period of SCL t LOW 1.3 µs High Period of SCL t HIGH 0.6 µs Data Hold Time t HD:DAT 0 0.9 µs Data Setup Time t SU:DAT 100 ns Start Setup time t SU:STA 0.6 µs SDA and SCL Rise Time t R (Note 6) 20 + 0.1C B 300 ns SDA and SCL Fall Time t F (Note 6) 20 + 0.1C B 300 ns Stop Setup Time t SU:STO 0.6 µs SDA and SCL Capacitive Loading C B (Note 6) 400 pf EEPROM Write Time t WR (Note 7) 10 20 ms NONVOLATILE MEMORY CHARACTERISTICS ( = +2.7V to +5.5V, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS EEPROM Writes +70 C (Note 4) 50,000 Note 1: All voltages referenced to ground. Note 2: I STBY is specified with SDA = SCL =, outputs floating, and inputs connected to or GND. Note 3: The does not obstruct the SDA and SCL lines if is switched off as long as the voltages applied to these inputs do not violate their minimum and maximum input voltage levels. Note 4: Guaranteed by design. Note 5: Timing shown is for fast-mode (400kHz) operation. This device is also backward compatible with I 2 C standard-mode timing. Note 6: C B total capacitance of one bus line in picofarads. Note 7: EEPROM write time applies to all the EEPROM memory and SRAM shadowed EEPROM memory when SEE = 0. The EEPROM write time begins after a stop condition occurs. 3

( = +5.0V, T A = +25 C, unless otherwise noted.) SUPPLY CURRENT (µa) SUPPLY CURRENT vs. SUPPLY VOLTAGE 2.0 I/O0 I/O7 CONTROL BITS = 0 I/O0 I/O7 PULLUPS DISABLED = SDA = SCL 1.5 1.0 0.5 toc01 Typical Operating Characteristics SUPPLY CURRENT (µa) 2.5 2.0 1.5 1.0 0.5 SUPPLY CURRENT vs. TEMPERATURE I/O0 I/O7 CONTROL BITS = 0 I/O0 I/O7 PULLUPS DISABLED = SDA = SCL = 5V toc02 0 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE (V) 0-40 -20 0 20 40 TEMPERATURE ( C) 60 80 20 18 16 SUPPLY CURRENT vs. SCL FREQUENCY = SDA = 5V toc03 6 5 I/O OUTPUT VOLTAGE vs. SUPPLY VOLTAGE PULLUPS ENABLED PULLDOWNS DISABLED toc04 SUPPLY CURRENT (µa) 14 12 10 8 6 I/O VOLTAGE (V) 4 3 2 HIGH IMPEDANCE 4 2 1 EEPROM RECALL AT V POR 0 0 100 200 300 400 SCL FREQUENCY (khz) 0 0 1 2 3 4 5 6 SUPPLY VOLTAGE (V) 4

PIN NAME FUNCTION 1 I/O_0 Input/Output 0. Bidirectional I/O pin. 2 I/O_1 Input/Output 1. Bidirectional I/O pin. 3 I/O_2 Input/Output 2. Bidirectional I/O pin. 4 I/O_3 Input/Output 3. Bidirectional I/O pin. 5 I/O_4 Input/Output 4. Bidirectional I/O pin. 6 A0 I 2 C Address Input. Inputs A0, A1, and A2 determine the I 2 C slave address of the device. 7 A1 I 2 C Address Input. Inputs A0, A1, and A2 determine the I 2 C slave address of the device. 8 Power-Supply Voltage 9 SDA I 2 C Serial Data Open-Drain Input/Output 10 SCL I 2 C Serial Clock Input 11 A2 I 2 C Address Input. Inputs A0, A1, and A2 determine the I 2 C slave address of the device. 12 I/O_5 Input/Output 5. Bidirectional I/O pin. 13 I/O_6 Input/Output 6. Bidirectional I/O pin. 14 I/O_7 Input/Output 7. Bidirectional I/O pin. 15 I/O_8 Input/Output 8. Bidirectional I/O pin. 16 GND Ground Pin Description Block Diagram SDA SCL A0 A1 A2 I 2 C INTERFACE I/O CONTROL REGISTERS PULLUP ENABLE (F0h-F1h) I/O CELL (x9) R PU GND I/O CONTROL (F2h-F3h) I/O_n [n = 0 TO 8] EEPROM 64 BYTES USER MEMORY [00h TO 3Fh] I/O STATUS (F8h-F9h) 5

Detailed Description The contains nine bidirectional, NV, input/output (I/O) pins, and a 64-byte EEPROM user memory. The I/O pins and user memory are accessible through an I 2 C-compatible serial bus. Programmable NV I/O Pins Each programmable I/O pin consists of an input and an open-collector output with a selectable internal pullup resistor. To enable the pullups for each I/O pin, write to the Pullup Enable Registers (F0h and F1h). To pull the output low or place the pulldown transistor into a highimpedance state, write to the I/O Control Registers (F2h and F3h). To read the voltage levels present on the I/O pins, read the I/O Status Registers (F8h and F9h). To determine the status of the output register, read the I/O Control Registers and the Pullup Resistor Registers. The I/O Control Registers and the Pullup Enable Registers are all SRAM shadowed EEPROM registers. It is possible to disable the EEPROM writes of the registers using the SEE bit in the Configuration Register. This reduces the time required to write to the register and increases the amount of times the I/O pins can be adjusted before the EEPROM is worn out. Memory Map and Memory Types The memory map is shown in Table 1. Three different types of memory are present in the : EEPROM, SRAM shadowed EEPROM, and SRAM. Memory locations specified as EEPROM are NV. Writing to these locations results in an EEPROM write cycle for a time specified by t WR in the AC Electrical Characteristics table. Locations specified as SRAM shadowed EEPROM can be configured to operate in one of two modes specified by the SEE bit (the LSB of the Configuration Register, F4h). When the SEE bit = 0 (default), the memory location acts like EEPROM. However, when SEE = 1, shadow SRAM is written to instead of the EEPROM. This eliminates both the EEPROM write time, t RW, as well as the concern of wearing out the EEPROM. This is ideal for applications that wish to constantly write to the I/Os. Power-up default states can be programmed for the I/Os in EEPROM (with SEE = 0) and then once powered-up, SEE can be written to a 1 so the I/Os can be updated periodically in SRAM. The final type of memory present in the is standard SRAM. Slave Address and Address Pins The s slave address is determined by the state of the A0, A1, and A2 address pins as shown in Figure 1. Address pins connected to GND result in a 0 in the corresponding bit position in the slave address. Conversely, address pins connected to result in a 1 in the corresponding bit positions. I 2 C communication is described in detail in a later section. I 2 C Serial Interface Description I 2 C Definitions The following terminology is commonly used to describe I 2 C data transfers. Master Device: The master device controls the slave devices on the bus. The master device generates SCL clock pulses, start, and stop conditions. Slave Devices: Slave devices send and receive data at the master s request. Bus Idle or Not Busy: Time between stop and start conditions when both SDA and SCL are inactive and in their logic-high states. When the bus is idle it often initiates a low-power mode for slave devices. Start Condition: A start condition is generated by the master to initiate a new data transfer with a slave. Transitioning SDA from high to low while SCL remains high generates a start condition. See the timing diagram for applicable timing. Stop Condition: A stop condition is generated by the master to end a data transfer with a slave. Transitioning SDA from low to high while SCL remains high generates a stop condition. See the timing diagram for applicable timing. Repeated Start Condition: The master can use a repeated start condition at the end of one data transfer to indicate that it immediately initiates a new data transfer following the current one. Repeated starts are commonly used during read operations to identify a specific memory address to begin a data transfer. A repeated start condition is issued identically to a normal start condition. See the timing diagram for applicable timing. Bit Write: Transitions of SDA must occur during the low state of SCL. The data on SDA must remain valid and unchanged during the entire high pulse of SCL plus the setup and hold time requirements (see Figure 2). Data is shifted into the device during the rising edge of the SCL. 6

Table 1. Memory Map ADDRESS TYPE NAME FUNCTION FACTORY DEFAULT 00h to 3Fh EEPROM User Memory 64 bytes of general-purpose user EEPROM. 00h 40 to E7h Reserved Undefined address space for future expansion. Reads and writes to this space have no effect on the device. E8 to EFh EEPROM Reserved F0h F1h Pullup Enable 0 Pullup Enable 1 SRAM F2h Shadowed EEPROM I/O Control 0 [EEPROM writes are disabled if F3h the SEE I/O Control 1 bit = 1] Pullup enable for I/O_0 to I/O_7. I/O_0 is the LSB and I/O_7 is the MSB. Set the corresponding bit to enable the pullup; clear the bit to disable the pullup. Pullup enable for I/O_8. I/O_8 is the LSB. Only the LSB is used. Set the LSB bit to enable the pullup on I/O_8; clear the LSB to disable the pullup. I/O control for I/O_0 to I/O_7. I/O_0 is the LSB and I/O_7 is the MSB. Clearing the corresponding bit of the register pulls the selected I/O pin low; setting the bit places the pulldown transistor into a high-impedance state. When the pulldown is high impedance, the output floats if no pullup/down is connected to the pin. I/O control for I/O_8. I/O_8 is the LSB. Only the LSB is used. Clearing the LSB of the register pulls the I/O_8 pin low; setting the LSB places the pulldown transistor into a high-impedance state. When the pulldown is high impedance, the output floats if no pullup/down is connected to the pin. 00h 00h FFh 01h F4h Configuration Configuration register. The LSB is the SEE bit. When set, this bit disables writes to the EEPROM; writing only affects the shadow SRAM. When set to 0, both the EEPROM and the shadow SRAM is written. 00h F5h to F7h F8h I/O Status 0 SRAM F9h I/O Status 1 FAh to FFh User Memory 3 bytes of general-purpose user EEPROM. 00h SRAM User I/O status for I/O_0 to I/O_7. I/O_0 is the LSB and I/O_7 is the MSB. Writing to this register has no effect. Read this register to determine the state of the I/O_0 to I/O_7 pins. I/O status for I/O_8. I/O_8 is the LSB. Only the LSB is used; the other bits could be any value when read. Writing to this register has no effect. Read this register to determine the state of the I/O_8 pin. 6 bytes of general-purpose SRAM. MSB 1 LSB 0 1 0 A2 A1 A0 R/W ADDRESS* READ/WRITE BIT *THE ADDRESS IS DETERMINED BY ADDRESS PINS A0, A1, AND A2. Figure 1. Slave Address Byte 7

Bit Read: At the end a write operation, the master must release the SDA bus line for the proper amount of setup time before the next rising edge of SCL during a bit read (see Figure 2). The device shifts out each bit of data on SDA at the falling edge of the previous SCL pulse and the data bit is valid at the rising edge of the current SCL pulse. Remember that the master generates all SCL clock pulses including when it is reading bits from the slave. Acknowledgement ( and N): An acknowledgement () or not acknowledge (N) is always the 9th bit transmitted during a byte transfer. The device receiving data (the master during a read or the slave during a write operation) performs an by transmitting a zero during the 9th bit. A device performs a N by transmitting a one during the 9th bit. Timing (Figure 2) for the and N is identical to all other bit writes. An is the acknowledgement that the device is properly receiving data. A N is used to terminate a read sequence or as an indication that the device is not receiving data. Byte Write: A byte write consists of 8 bits of information transferred from the master to the slave (most significant bit first) plus a 1-bit acknowledgement from the slave to the master. The 8 bits transmitted by the master are done according to the bit write definition and the acknowledgement is read using the bit read definition. Byte Read: A byte read is an 8-bit information transfer from the slave to the master plus a 1-bit or N from the master to the slave. The 8 bits of information that are transferred (most significant bit first) from the slave to the master are read by the master using the bit read definition above, and the master transmits an using the bit write definition to receive additional data bytes. The master must N the last byte read to terminated communication so the slave returns control of SDA to the master. Slave Address Byte: Each slave on the I 2 C bus responds to a slave address byte sent immediately following a start condition. The slave address byte contains the slave address in the most significant 7 bits and the R/W bit in the least significant bit. The s slave address is determined by the state of the A0, A1, and A2 address pins as shown in Figure 1. Address pins connected to GND result in a 0 in the corresponding bit position in the slave address. Conversely, address pins connected to result in a 1 in the corresponding bit positions. When the R/W bit is 0 (such as in A0h), the master is indicating it will write data to the slave. If R/W = 1, (A1h in this case), the master is indicating it will read from the slave. SDA t BUF t HD:STA t SP t LOW t R t F SCL t HD:STA t HIGH t SU:STA t HD:DAT t SU:DAT REPEATED t SU:STO NOTE: TIMING IS REFERENCED TO V IL(MAX) AND V IH(MIN) Figure 2. I 2 C Timing Diagram 8

If an incorrect slave address is written, the assumes the master is communicating with another I 2 C device and ignores the communication until the next start condition is sent. Memory Address: During an I 2 C write operation, the master must transmit a memory address to identify the memory location where the slave is to store the data. The memory address is always the second byte transmitted during a write operation following the slave address byte. I 2 C Communication Writing a Single Byte to a Slave: The master must generate a start condition, write the slave address byte (R/W = 0), write the memory address, write the byte of data, and generate a stop condition. Remember the master must read the slave s acknowledgement during all byte write operations. Writing Multiple Bytes to a Slave: To write multiple bytes to a slave, the master generates a start condition, writes the slave address byte (R/W = 0), writes the memory address, writes up to 8 data bytes, and generates a stop condition. The is capable of writing up to 8 bytes (one page or row) with a single write transaction. This is internally controlled by an address counter that allows data to be written to consecutive addresses without transmitting a memory address before each data byte is sent. The address counter limits the write to one 8- byte page. Attempts to write to additional pages of memory without sending a stop condition between pages results in the address counter wrapping around to the beginning of the present row. The first row begins at address 00h and subsequent rows begin at multiples of 8 there on (08h, 10h, 18h, 20h, etc). To prevent address wrapping from occurring, the master must send a stop condition at the end of the page, and then wait for the bus free or EEPROM write time to elapse. Then the master can generate a new start condition, write the slave address byte (R/W = 0), and the first memory address of the next memory row before continuing to write data. Acknowledge Polling: Any time an EEPROM page is written, the requires the EEPROM write time (t W ) after the stop condition to write the contents of the page to EEPROM. During the EEPROM write time, the device does not acknowledge its slave address because it is busy. It is possible to take advantage of this phenomenon by repeatedly addressing the, which allows communication to continue as soon as the device is ready. The alternative to acknowledge polling is to wait for a maximum period of t W to elapse before attempting to access the device. EEPROM Write Cycles: When EEPROM writes occur, the writes the whole EEPROM memory page even if only a single byte on a page was modified. Writes that do not modify all 8 bytes on the page are valid and do not corrupt any other bytes on the same page. Because the whole page is written, even bytes on the page that were not modified during the transaction are still subject to a write cycle. The s EEPROM write cycles are specified in the Nonvolatile Memory Characteristics table. The specification shown is at the worst-case temperature. It is capable of handling approximately 10x that many writes at room temperature. Reading a Single Byte from a Slave: Unlike the write operation that uses the specified memory address byte to define where the data is to be written, the read operation occurs at the present value of the memory address counter. To read a single byte from the slave, the master generates a start condition, writes the slave address byte with R/W = 1, reads the data byte with a N to indicate the end of the transfer, and generates a stop condition. However, since requiring the master to keep track of the memory address counter is impractical, the following method should be used to perform reads from a specified memory location. Manipulating the Address Counter for Reads: A dummy write cycle can be used to force the address counter to a particular value. To do this the master generates a start condition, writes the slave address byte (R/W = 0), writes the memory address where it desires to read, generates a repeated start condition, writes the slave address byte (R/W = 1), reads data with or N as applicable, and generates a stop condition. 9

TYPICAL I2C WRITE TRANSACTION MSB LSB MSB LSB MSB LSB 1 0 1 0 A2 A1 A0 R/W b7 b6 b5 b4 b3 b2 b1 b0 b7 b6 b5 b4 b3 b2 b1 b0 ADDRESS* READ/ WRITE REGISTER ADDRESS DATA *THE ADDRESS IS DETERMINED BY ADDRESS PINS A0, A1, AND A2. EXAMPLE I2C TRANSACTIONS (WHEN A0, A1, AND A2 ARE CONNECTED TO GND) A) SINGLE BYTE WRITE -WRITE I/O CONTROL 0 REGISTER TO 00h A0h F2h 1 0100000 11110 010 00000 000 B) SINGLE BYTE READ -READ I/O STATUS 0 RESISTER A0h F8h 1 0100000 11111 000 REPEATED A1h 10100 001 DATA I/O STATUS MASTER N C) SINGLE BYTE WRITE -WRITE PULLUP ENABLE 0 REGISTER TO FFh A0h F0h 1 0100000 11110000 FFh 1 1 111 111 D) TWO BYTE WRITE -WRITE I/O CONTROL 0 AND I/O CONTROL 1 REGISTERS TO 00h A0h F2h 1 0100000 11110 010 00h 00000000 00h 00000000 D) TWO BYTE READ -READ I/O STATUS 0 AND I/O STATUS 1 RGISTERS A0h F8h A1h DATA 101000 00 REPEATED 111 11000 1010 0001 I/O STATUS 0 MASTER DATA I/O STATUS 1 MASTER N Figure 3. I 2 C Communication Examples See Figure 3 for a read example using the repeated start condition to specify the starting memory location. Reading Multiple Bytes from a Slave: The read operation can be used to read multiple bytes with a single transfer. When reading bytes from the slave, the master simply s the data byte if it desires to read another byte before terminating the transaction. After the master reads the last byte it must N to indicate the end of the transfer and generates a stop condition. Applications Information Power-Supply Decoupling To achieve best results, it is highly recommended that a decoupling capacitor is used on the IC power-supply pins. Typical values of decoupling capacitors are 0.01µF and 0.1µF. Use a high-quality, ceramic, surface-mount capacitor, and mount it as close as possible to the and GND pins of the IC to minimize lead inductance. TRANSISTOR COUNT: 14,398 SUBSTRATE CONNECTED TO GROUND Chip Topology Package Information For the latest package outline information, go to www.maxim-ic.com/dallaspackinfo. Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 10 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. is a registered trademark of Dallas Semiconductor Corporation.

ENGLISH?????????? WHAT'S NEW PRODUCTS SOLUTIONS DESIGN APPNOTES SUPPORT BUY COMPANY MEMBERS Part Number Table Notes: 1. 2. 3. 4. 5. See the QuickView Data Sheet for further information on this product family or download the full data sheet (PDF, 984kB). Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales. Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day. Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: See full data sheet or Part Naming Conventions. * Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Part Number Free Sample Buy Direct Package: TYPE PINS SIZE DRAWING CODE/VAR * Temp RoHS/Lead-Free? Materials Analysis E+ E E+TRL TSSOP;16 pin;173 Dwg: 56-G2019-000A (PDF) Use pkgcode/variation: U16+1* TSSOP;16 pin;173 Dwg: 56-G2019-000A (PDF) Use pkgcode/variation: U16-1* TSSOP;16 pin;173 Dwg: 56-G2019-000A (PDF) Use pkgcode/variation: U16+1* -40C to +85C RoHS/Lead-Free: Yes Materials Analysis -40C to +85C RoHS/Lead-Free: No Materials Analysis -40C to +85C RoHS/Lead-Free: Yes Materials Analysis Didn't Find What You Need? CONTACT US: SEND US AN EMAIL C opyright 2007 by Maxim Integrated Products, Dallas Semiconductor Legal Notices P rivacy P olicy