X24F064/032/016

7

Current Address Read

Internally, the X24F064/032/016 contains an ad-

dress counter that maintains the address of the last

byte read, incremented by one byte. Therefore, if the

last read was from address n, the next read opera-

tion accesses data from address n + 1. Upon receipt

of the slave address with the R/W set HIGH, the

X24F064/032/016 issues an acknowledge and trans-

mits the eight-bit word. The read operation is termi-

nated by the master; by not responding with an

acknowledge and by issuing a stop condition. Refer

to Figure 6 for the sequence of address, acknowl-

edge and data transfer.

Random Read

Random read operations allow the master to access

any memory location in a random manner. Prior to is-

suing the slave address with the R/W bit set HIGH, the

master must first perform a “dummy” write operation.

The master issues the start condition, and the slave ad-

dress with the R/W bit set LOW, followed by the byte

address it is to read. After the byte address acknowl-

edge, the master immediately reissues the start condi-

tion and the slave address with the R/W bit set HIGH.

This will be followed by an acknowledge from the

X24F064/032/016 and then by the eight-bit byte. The

read operation is terminated by the master; by not re-

sponding with an acknowledge and by issuing a stop

condition. Refer to Figure 7 for the address, acknowl-

edge and data transfer sequence.

Figure 7. Random Read

BUS ACTIVITY:

MASTER

SDA LINE

BUS ACTIVITY:

X24F016/032/064

S

T

A

R

T

SLAVE

ADDRESS

S

A

C

K

6686 ILL F12.3

S

T

A

R

T

S

BYTE

ADDRESS n

A

C

K

SLAVE

ADDRESS

DATA n

A

C

K

S

T

O

P

P

Figure 6. Current Address Read

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

DATA

6686 ILL F11.1