The SDA pin is generally pulled large by having an exter-nal gadget. Knowledge to the SDA pin may adjust only all through SCL lower time durations.

Details variations in the course of SCL large durations will point out a get started or end ailment asdefined beneath.Knowledge ValiditySTART Ailment: A high-to-low changeover of SDA with SCL higher is actually a commence conditionthat need to precede every other command.

Get started and Prevent DefinitionSTOP Problem: A low-to-high changeover of SDA with SCL higher is really a prevent problem.Following a read through sequence, the quit command will place the EEPROM inside a standby powermode .Admit: All addresses and facts words and phrases are serially transmitted to and fromthe EEPROM in 8-bit terms.

The EEPROM sends a “0” to accept that it hasreceived each and every term. This transpires during the ninth clock cycle.STANDBY Manner: The AT24C02A/04A/08A/16A characteristics a low-power standby modethat is enabled: (a) on power-up and (b) following the receipt of your Cease little bit as well as com-pletion of any internal operations.

Soon after an interruption in protocol, energy decline or process reset, anytwo-wire component may be reset by pursuing these steps: one. Clock around nine cycles2. Appear for SDA large in each individual cycle while SCL is high3. Develop a start condition as SDA is substantial.

The machine address phrase is made up of the necessary one, zero sequence with the very first fourmost significant bits as shown.

This is certainly popular to every one of the EEPROM equipment.The next three bits would be the A2, A1 and A0 gadget deal with bits to the 1K/2K EEPROM.These three bits will have to examine for their corresponding hard-wired input pins.The 4K EEPROM only makes use of the A2 and A1 gadget tackle bits using the 3rd little bit staying amemory website page deal with little bit.

The 2 unit handle bits ought to examine to their corre-sponding hard-wired enter pins. The A0 pin isn't any link.The 8K EEPROM only employs the A2 system deal with little bit using the subsequent two bits currently being formemory web site addressing.

The A2 little bit must compare to its corresponding hard-wiredinput pin. The A1 and A0 pins are not any join.The 16K won't use any device handle bits but rather the 3 bits are utilized for mem-ory web page addressing.

These web site addressing bits within the 4K, 8K and 16K devicesshould be deemed quite possibly the most important bits of the info phrase address which follows.The A0, A1 and A2 pins aren't any connect.The eighth bit of your device tackle is definitely the read/write procedure decide on little bit.

A read opera-tion is initiated if this bit is superior in addition to a create procedure is initiated if this little bit is lower.Upon a review on the product tackle, the EEPROM will output a zero. If a evaluate isnot produced, the chip will return to your standby state.

       This involvessending a start condition followed by the device addressword. The read/write bit is representative of the operationdesired. Only if the internal write cycle has completed willthe EEPROM respond with a zero allowing the read orwrite sequence to continue.Read OperationsRead operations are initiated the same way as write opera-tions with the exception that the read/write select bit in thedevice address word is set to one.

　　There are two readoperations: byte read and sequential read.BYTE READ: A byte read is initiated with a start conditionfollowed by a 7-bit data word address and a high read bit.The AT24C01 will respond with an acknowledge and thenserially output 8 data bits.

　　The microcontroller does notrespond with a zero but does generate a following stopcondition (refer to Figure 3).SEQUENTIAL READ: Sequential reads are initiated thesame as a byte read. After the microcontroller receives an8-bit data word, it responds with an acknowledge.

　　As longas the EEPROM receives an acknowledge, it will continueto increment the data word address and serially clock outsequential data words. When the memory address limit isreached, the data word address will “roll over” and thesequential read will continue.

　　The sequential read opera-tion is terminated when the microcontroller does notrespond with an input zero but does generate a followingstop condition (refer to Figure 4).