X24164
Page Write
Flow 1. ACK Polling Sequence
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
transmituptofifteenmorewords. Afterthereceiptofeach
word, the X24164 will respond with an acknowledge.
WRITE OPERATION
COMPLETED
ENTER ACK POLLING
ISSUE
START
Afterthereceiptofeachword,thefourloworderaddress
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.
RefertoFigure6fortheaddress, acknowledgeanddata
transfer sequence.
ISSUE SLAVE
ADDRESS AND R/W = 0
ISSUE STOP
ACK
NO
RETURNED?
Acknowledge Polling
YES
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.
NEXT
NO
OPERATION
A WRITE?
YES
ISSUE BYTE
ADDRESS
ISSUE STOP
PROCEED
PROCEED
3846 FHD F12
Figure 6. Page Write
S
T
S
T
O
P
SLAVE
ADDRESS
A
R
T
BUS ACTIVITY:
MASTER
WORD ADDRESS (n)
DATA n
DATA n+1
DATA n+15
SDA LINE
S
P
A
C
K
A
C
K
A
C
K
A
C
K
A
C
K
BUS ACTIVITY:
X24164
NOTE: In this example n = xxxx 0000 (B); x = 1 or 0
3846 FHD F13
6
XICOR [ XICOR INC. ]
