Datasheet

 2009 Microchip Technology Inc. DS21682E-page 11
24LCS22A
5.0 ACKNOWLEDGE POLLING
Since the device will not acknowledge during a write
cycle, this can be used to determine when the cycle is
complete (this feature can be used to maximize bus
throughput). Once the Stop condition for a Write
command has been issued from the master, the device
initiates the internally timed write cycle. ACK polling
can be initiated immediately. This involves the master
sending a Start condition followed by the control byte
for a Write command (R/W
= 0). If the device is still
busy with the write cycle, then no ACK will be returned.
If the cycle is complete, then the device will return the
ACK and the master can then proceed with the next
Read or Write command. See Figure 5-1 for the flow
diagram.
FIGURE 5-1: ACKNOWLEDGE
POLLING FLOW
FIGURE 5-2: PAGE WRITE
Did Device
Acknowledge
(ACK = 0)?
Send
Write Command
Send Stop
Condition to
Initiate Write Cycle
Send Start
Send Control Byte
with R/W
= 0
Next
Operation
No
Yes
SDA Line
Control
Byte
Word
Address
S
T
O
P
S
T
A
R
T
A
C
K
A
C
K
A
C
K
A
C
K
A
C
K
Data n + 1
Data n + 7
Data (n)
P
S
VCLK
Bus Activity
Master
Bus Activity