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The SCL enter is used to positiveedge clock facts into every EEPROM product and negativeedge clock information from each device.SERIAL Information (SDA): The SDA pin is bi-directional forserial facts transfer.

This pin is open-drain pushed and maybe wire-ORed with any amount of other open-drain oropen-collector devices.DEVICE/PAGE ADDRESSES (A2, A1, A0): The A2, A1and A0 pins are machine tackle inputs that are tough wiredfor the AT24C01A along with the AT24C02.

As a lot of as eight1K/2K equipment may well be addressed on the one bus program(product addressing is reviewed in detail under the DeviceAddressing segment).The AT24C04 takes advantage of the A2 and A1 inputs for really hard wireaddressing in addition to a whole of 4 4K products might beaddressed with a single bus system.

The A0 pin is ano link.The AT24C08 only utilizes the A2 input for hardwire address-ing plus a full of two 8K units could be addressed on asingle bus technique. The A0 and A1 pins are no connects.The AT24C16 does not make use of the unit handle pins, whichlimits the number of units with a one bus to at least one.

TheA0, A1 and A2 pins are not any connects.Create Guard (WP): The AT24C01A/02/04/16 has aWrite Shield pin that provides components info defense.The Publish Shield pin will allow usual read/write operationswhen linked to ground (GND).

If the Compose Protectpin is linked to VCC, the generate defense aspect isenabled and operates as revealed within the pursuing desk.

Accept POLLING: When the internally-timedwrite cycle has began plus the EEPROM inputs are dis-abled, acknowledge polling might be initiated. This involvessending a start off affliction followed by the gadget addressword.

The read/write little bit is consultant from the operationdesired. Only if the internal compose cycle has completed willthe EEPROM react that has a zero allowing the read orwrite sequence to carry on.Examine OperationsRead functions are initiated the identical way as produce opera-tions using the exception the read/write select bit in thedevice handle word is about to one. You can find two readoperations: byte study and sequential go through.

BYTE Read: A byte read is initiated that has a commence conditionfollowed by a 7-bit details term deal with along with a significant browse little bit.The AT24C01 will answer with an admit and thenserially output eight info bits. The microcontroller does notrespond using a zero but does deliver a pursuing stopcondition.

SEQUENTIAL Read through: Sequential reads are initiated thesame as being a byte study. Right after the microcontroller receives an8-bit data phrase, it responds with an acknowledge. As longas the EEPROM receives an acknowledge, it will eventually continueto increment the info term handle and serially clock outsequential data phrases.

When the memory tackle limit isreached, the info word tackle will “roll over” and thesequential examine will continue on. The sequential read through opera-tion is terminated if the microcontroller does notrespond with an enter zero but does generate a followingstop affliction.

　　The AK6420A/40A/80A is a 2048/4096/8192bit, serial, read/write, non-volatile memory device fabricated using anadvanced CMOS EEPROM technology. The AK6420A has 2048bits of memory organized into 128 registers of 16bits each.

　　The AK6440A has 4096bits of memory organized into 256 registers of 16 bits each.

　　The AK6480A has8192bits of memory organized into 512 registers of 16 bits each. The AK6420A/40A/80A can operate full functionunder wide operating voltage range from 1.8V to 5.5V.

　　The charge up circuit is integrated for high voltage generationthat is used for write operation.The AK6420A/40A/80A can connect to the serial communication port of popular one chip microcomputer directly (3line negative clock synchronous interface).

　　At write operation, AK6420A/40A/80A takes in the write data from datainput pin (DI) to a register synchronously with rising edge of input pulse of serial clock pin (SK).

　　And at read operation,AK6420A/40A/80A takes out the read data from a register to data output pin (DO) synchronously with falling edge ofSK.The AK6420A/40A/80A has 4 instructions such as READ, WRITE, WREN (write enable) and WRDS (write disable).Each instruction is organized by op-code block (8bits), address block (8bits) and data (8bits × 2).

　　When input level ofSK pin is high level and input level of chip select (CS) pin is changed from high level to low level, AK6420A/40A/80Acan receive the instructions.