CAT1026, CAT1027
Preliminary Information
ACKNOWLEDGE
WRITE OPERATIONS
After a successful data transfer, each receiving device
is required to generate an acknowledge. The
acknowledging device pulls down the SDA line during
the ninth clock cycle, signaling that it received the 8 bits
of data.
Byte Write
In the Byte Write mode, the Master device sends the
STARTconditionandtheslaveaddressinformation(with
theR/Wbitsettozero)totheSlavedevice.AftertheSlave
generates an acknowledge, the Master sends a 8-bit
address that is to be written into the address pointers of
thedevice. Afterreceivinganotheracknowledgefromthe
Slave, the Master device transmits the data to be written
into the addressed memory location. The CAT1026 and
CAT1027 acknowledge once more and the Master
generates the STOP condition. At this time, the device
begins an internal programming cycle to non-volatile
memory. Whilethecycleisinprogress, thedevicewillnot
respond to any request from the Master device.
The CAT1026 and CAT1027 respond with an
acknowledge after receiving a START condition and its
slave address. If the device has been selected along
with a write operation, it responds with an acknowledge
after receiving each 8-bit byte.
When the CAT1026 and CAT1027 begin a READ mode
it transmits 8 bits of data, releases the SDA line and
monitors the line for an acknowledge. Once it receives
this acknowledge, the CAT1026 and CAT1027 will
continue to transmit data. If no acknowledge is sent by
theMaster,thedeviceterminatesdatatransmissionand
waits for a STOP condition.
Figure 6. Start/Stop Timing
SDA
SCL
START BIT
STOP BIT
Figure 7. Acknowledge Timing
SCL FROM
MASTER
1
8
9
DATA OUTPUT
FROM TRANSMITTER
DATA OUTPUT
FROM RECEIVER
START
ACKNOWLEDGE
Figure 8. Slave Address Bits
Default Configuration
1
0
1
0
0
0
0
R/W
CAT
Doc. No. 3010, Rev. E
10
CATALYST [ CATALYST SEMICONDUCTOR ]
