Send a boot condition after the device address

Read operations are initiated the same way as write operations with the exception that theread/write select bit in the device address word is set to one. There are three read operations:current address read, random address read and sequential read.

CURRENT ADDRESS READ: The internal data word address counter maintains the lastaddress accessed during the last read or write operation, incremented by one. This addressstays valid between operations as long as the chip power is maintained.

The address “rollover” during read is from the last byte of the last memory page to the first byte of the first page.The address “roll over” during write is from the last byte of the current page to the first byte ofthe same page.Once the device address with the read/write select bit set to one is clocked in and acknowl-edged by the EEPROM, the current address data word is serially clocked out. Themicrocontroller does not respond with an input zero but does generate a following stop condi-tion.

RANDOM READ: A random read requires a “dummy” byte write sequence to load in the dataword address. Once the device address word and data word address are clocked in andacknowledged by the EEPROM, the microcontroller must generate another start condition.The microcontroller now initiates a current address read by sending a device address with theread/write select bit high.

The EEPROM acknowledges the device address and serially clocksout the data word. The microcontroller does not respond with a zero but does generate a fol-lowing stop condition.SEQUENTIAL READ: Sequential reads are initiated by either a current address read or a ran-dom address read. After the microcontroller receives a data word, it responds with anacknowledge.

As long as the EEPROM receives an acknowledge, it will continue to incrementthe data word address and serially clock out sequential data words. When the memoryaddress limit is reached, the data word address will “roll over” and the sequential read will con-tinue. The sequential read operation is terminated when the microcontroller does not respondwith a zero but does generate a following stop condition.