X24F064/032/016

5

DEVICE ADDRESSING

Following a start condition the master must output the

address of the slave it is accessing (see Figure 4). The

next two bits are the device select bits. A system could

have up to eight X24F032/016’s on the bus or up to

four 24F064’s on the bus. The device addresses are

some of the slave addresses must be the inverse of

the corresponding input pin.

Figure 4. Slave Address

6686 ILL F07.4

S2

A9

A8

R/W

DEVICE

SELECT

S1

A12

HIGH ORDER

SECTOR ADDRESS

A11

A10

X24F064

S2

A9

A8

R/W

DEVICE

SELECT

S1

S0

HIGH ORDER

SECTOR ADDRESS

A11

A10

X24F032

1

A9

A8

R/W

DEVICE

TYPE

IDENTIFIER

S2

S1

HIGH ORDER

SECTOR ADDRESS

S0

A10

X24F016

DEVICE

SELECT

Also included in the slave address is an extension of

the array’s address which is concatenated with the

eight bits of address in the sector address field,

providing direct access to the entire SerialFlash

Memory array.

The last bit of the slave address defines the operation

to be performed. When set HIGH a read operation is

selected, when set LOW a program operation is

selected.

Following the start condition, the X24F064/032/016

monitors the SDA bus comparing the slave address

being transmitted with its slave address device type

identifier. Upon a correct comparison of the device

select

inputs,

the

X24F064/032/016

outputs

an

acknowledge on the SDA line. Depending on the state

of the R/W bit, the X24F064/032/016 will execute a

read or program operation.

PROGRAMMING OPERATIONS

The X24F064/032/016 offers a 32-byte sector pro-

gramming operation. For a program operation, the

X24F064/032/016 requires a second address field.

This field contains the address of the first byte in the

sector. Upon receipt of the address, comprised of

eight bits, the X24F064/032/016 responds with an ac-

knowledge and awaits the next eight bits of data,

again responding with an acknowledge. The master

then transmits 31 more bytes. After the receipt of

each byte, the X24F064/032/016 will respond with an

acknowledge.

Figure 5. Sector Programming

BUS ACTIVITY:

MASTER

SDA LINE

BUS ACTIVITY:

X24F016/032/064

S

T

A

R

T

SLAVE

ADDRESS

S

S

T

O

P

P

A

C

K

A

C

K

A

C

K

A

C

K

A

C

K

SECTOR ADDRESS

DATA n

DATA n+1

DATA n+31

6686 ILL F10.3