10

AT24C01B [Preliminary]

5156B–SEEPR–5/06

byte of the first page. The address “roll over” during write is from the last byte of the current

page to the first byte of the 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. The

microcontroller does not respond with an input zero but does generate a following stop condi-

tion (see Figure 10 on page 11).

RANDOM READ: A random read requires a “dummy” byte write sequence to load in the data

word address. Once the device address word and data word address are clocked in and

acknowledged by the EEPROM, the microcontroller must generate another start condition.

The microcontroller now initiates a current address read by sending a device address with the

read/write select bit high. The EEPROM acknowledges the device address and serially clocks

out the data word. The microcontroller does not respond with a zero but does generate a fol-

lowing stop condition (see Figure 11 on page 12).

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 an

acknowledge. As long as the EEPROM receives an acknowledge, it will continue to increment

the data word address and serially clock out sequential data words. When the memory

address 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 respond

with a zero but does generate a following stop condition (see Figure 12 on page 12).