24AA025 Datasheet, PDF (18/42 Pages) Microchip Technology – I2C™ Serial EEPROM Family Data Sheet

24AAXX/24LCXX/24FCXX
7.0 ACKNOWLEDGE POLLING
Since the device will not acknowledge commands
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 con-
trol 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 no ACK is returned, the Start bit and control
byte must be re-sent. If the cycle is complete, then the
device will return the ACK and the master can then pro-
ceed with the next Read or Write command. See
Figure 7-1 for flow diagram.
FIGURE 7-1:
ACKNOWLEDGE
POLLING FLOW
Send
Write Command
Send Stop
Condition to
Initiate Write Cycle
Send Start
Send Control Byte
with R/W = 0
Did Device
No
Acknowledge
(ACK = 0)?
Yes
Next
Operation
DS21930B-page 18
© 2007 Microchip Technology Inc.