AT30TSE758A_14 Datasheet, PDF (37/57 Pages) ATMEL Corporation – Digital Temperature Sensor with Nonvolatile Registers

10.3 Write Operations
The Serial EEPROM within the AT30TSE752A/754A/758A supports single byte writes up to a full 16 bytes per page. The
only difference between a Byte Write and a Page Write protocol sequence is the amount of data bytes loaded.
Regardless of whether a Byte Write or Page Write operation is performed, it will take the same amount of time to write
the data to the addressed memory location(s). The internal write cycle will complete in the minimum t_WR specification.
10.3.1 Byte Write
Following the Start condition from the Master, the device type identifier (1010), the device address bits and the R/W,
which is Logic 0 state, are placed onto the bus by the Master. This indicates to the addressed device that the Master will
follow by transmitting a byte with the word address. The AT30TSE752A/754A/758A will respond with an ACK during the
ninth clock cycle. Then the next byte transmitted by the Master is the 8-bit word address of the byte location in the
memory to be written. After receiving an ACK by the AT30TSE752A/754A/758A, the Master will transmit the data byte to
be written into the addressed memory location. The AT30TSE752A/754A/758A responds with an ACK and then the
Master generates a Stop condition. The Stop condition initiates the internal write cycle and, during this time, the
AT30TSE752A/754A/758A will not respond (NACK) to any valid protocol until the write cycle is complete. The internal
write cycle will complete in the minimum t_WR specification.
Figure 10-1. Byte Write to Serial EEPROM
SCL
12 3 4 567 89 12 345 67 89 123 45 67 89
Device Address Byte
Word Address Byte
Data Byte
SDA
1 0 1 0 A A/P1 A/P0 0 0 A7 A6 A5 A4 A3 A2 A1 A0 0 D7 D6 D5 D4 D3 D2 D1 D0 0
MSB
MSB
MSB
Start
by
Master
ACK
from
Slave
ACK
from
Slave
ACK
from
Slave
Stop
by
Master
10.3.2 Page Write
The device address byte, word address byte, and the first data byte are transmitted to the AT30TSE752A/754A/758A in
the same way as in the Byte Write protocol sequence. But instead of generating a Stop condition, the Master transmits
up to 16 data bytes to the AT30TSE752A/754A/758A, which are temporarily stored into an internal page buffer and will
be written into memory once the Master has generated the Stop condition. Upon receipt of each data byte, the four lower
order word address bits are internally incremented by one since the page size is 16 bytes. If the Master should transmit
more than 16 data bytes prior to generating the Stop condition, the address counter will roll over and the previously
received data will be replaced. As with the Byte Write operation, once the Stop condition is generated by the Master, then
the device's internal write cycle will begin. The internal write cycle will complete in the minimum t_WR specification. A very
important point to understand is that Page Write operations are limited to writing data bytes within a single physical page
regardless of the number of bytes actually being written.
Example: If a Page Write operation attempts to write across a physical page boundary, then the data will simply
rollover to the beginning of the same page and replace any existing data bytes previously loaded in the
page buffer.
AT30TSE752A/754A/758A [DATASHEET] 37
Atmel-8854G-DTS-AT30TSE752A-754A-758A-Datasheet_102014