Page "I²C" Paragraph 41

One specific example is the 24c32 type EEPROM, which uses two request bytes that are called Address High and Address Low.

( Accordingly, these EEPROMs aren't usable by pure SMBus hosts, which only support single byte commands or addresses.

) These bytes are used to address bytes within the 32 kbit ( 4 kB ) supported by that EEPROM ; the same two byte addressing is also used by larger EEPROMs, such as 24c512 ones storing 512 kbits ( 64 kB ).

Writing and reading data to these EEPROMs uses a simple protocol: the address is written, and then data is transferred until the end of the message.

( That data transfer part of the protocol also makes trouble for SMBus, since the data bytes are not preceded by a count and more than 32 bytes can be transferred at once.

I²C EEPROMs smaller than 32 kbits, such as 2 kbit 24c02 ones, are often used on SMBus with inefficient single byte data transfers.