X9118 Datasheet, PDF (5/20 Pages) Intersil Corporation – Dual Suply/Low Power/1024-Tap/2-Wire Bus

X9118
STOP CONDITION
All communications must be terminated by a stop
condition, which is a LOW to HIGH transition of SDA
while SCL is HIGH. See Figure 3.
ACKNOWLEDGE
Acknowledge is a software convention used to provide
a positive handshake between the master and slave
devices on the bus to indicate the successful receipt of
data. The transmitting device, either the master or the
slave, will release the SDA bus after transmitting eight
Figure 2. Acknowledge Response from Receiver
bits. The master generates a ninth clock cycle and
during this period the receiver pulls the SDA line LOW
to acknowledge that it successfully received the eight
bits of data.
The X9118 will respond with an acknowledge after
recognition of a start condition and its slave address
and once again after successful receipt of the
command byte. If the command is followed by a data
byte the X9118 will respond with a final acknowledge.
See Figure 2.
SCL from
Master
1
Data Output
from Transmitter
8
9
Data Output
from Receiver
START
ACKNOWLEDGE POLLING
The disabling of the inputs, during the internal
nonvolatile write operation, can be used to take
advantage of the typical 5ms EEPROM write cycle
time. Once the stop condition is issued to indicate the
end of the nonvolatile write command the X9118
initiates the internal write cycle. ACK polling, Flow 1,
can be initiated immediately. This involves issuing the
start condition followed by the device slave address. If
the X9118 is still busy with the write operation no ACK
will be returned. If the X9118 has completed the write
operation an ACK will be returned and the master can
then proceed with the next operation.
ACKNOWLEDGE
5
FN8161.1
March 25, 2005