X24164

6

WRITE OPERATION

COMPLETED

ENTER ACK POLLING

ISSUE

START

ISSUE SLAVE

ADDRESS AND R/W = 0

ACK

RETURNED?

NEXT

OPERATION

A WRITE?

ISSUE BYTE

ADDRESS

PROCEED

ISSUE STOP

NO

YES

YES

PROCEED

ISSUE STOP

NO

Flow 1. ACK Polling Sequence

Page Write

The X24164 is capable of a sixteen byte page write

operation. It is initiated in the same manner as the byte

write operation, but instead of terminating the write cycle

after the first data word is transferred, the master can

transmit up to fifteen more words. After the receipt of each

word, the X24164 will respond with an acknowledge.

After the receipt of each word, the four low order address

bits are internally incremented by one. The high order

seven bits of the word address remain constant. If the

master should transmit more than sixteen words prior to

generating the stop condition, the address counter will

“roll over” and the previously written data will be over-

written. As with the byte write operation, all inputs are

disabled until completion of the internal write cycle.

Refer to Figure 6 for the address, acknowledge and data

transfer sequence.

Acknowledge Polling

The disabling of the inputs can be used to take advan-

tage of the typical 5 ms write cycle time. Once the stop

condition is issued to indicate the end of the host’s write

operation the X24164 initiates the internal write cycle.

ACK polling can be initiated immediately. This involves

issuing the start condition followed by the slave address

for a write operation. If the X24164 is still busy with the

write operation no ACK will be returned. If the X24164

has completed the write operation an ACK will be

returned and the host can then proceed with the next

read or write operation. Refer to Flow 1.

3846 FHD F12

Figure 6. Page Write

BUS ACTIVITY:

MASTER

SDA LINE

BUS ACTIVITY:

X24164

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

WORD ADDRESS (n)

DATA n

DATA n+1

DATA n+15

NOTE: In this example n = xxxx 0000 (B); x = 1 or 0

3846 FHD F13