AT24C256C-SSHL-T Atmel, AT24C256C-SSHL-T Datasheet - Page 11

• Manufacturer Part Number: AT24C256C-SSHL-T
• Description: IC EEPROM 256KBIT IND 8SOIC
• Manufacturer: Atmel

Specifications of AT24C256C-SSHL-T

• Format - Memory: EEPROMs - Serial
• Memory Type: EEPROM
• Memory Size: 256K (32K x 8)
• Speed: 400kHz, 1MHz
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 1.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.
8568C–SEEPR–5/10
Read Operations
Read operations are initiated the same way as write operations with the exception that the read/write select bit in
the device address word is set to “1”. 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 last address accessed
during the last read or write operation, incremented by one. This address stays valid between operations as long
as the chip power is maintained. The address “roll over” during read is from the last byte of the last memory page,
to the first byte of the first page.
Once the device address with the read/write select bit set to “1” is clocked in and acknowledged by the EEPROM,
the current address data word is serially clocked out. The microcontroller does not respond with an input “0” but
does generate a following stop condition (refer to Figure 11).
Figure 7-1.
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 “0” but does generate a following
stop condition. (Refer to Figure 12)
Figure 7-2.
Note:
* = DON’T CARE bit
Current Address Read
Random Read
Atmel AT24C256C
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