isl22343 Intersil Corporation, isl22343 Datasheet - Page 14

• Manufacturer Part Number: isl22343
• Description: Quad Digitally Controlled Potentiometer Xdcp? , Low Noise, Low Power, I2c? Bus, 256 Taps
• Manufacturer: Intersil Corporation

SCL is HIGH (See Figure 16). A STOP condition at the end
of a read operation, or at the end of a write operation places
the device in its standby mode.
An ACK (Acknowledge) is a software convention used to
indicate a successful data transfer. The transmitting device,
either master or slave, releases the SDA bus after
transmitting eight bits. During the ninth clock cycle, the
receiver pulls the SDA line LOW to acknowledge the
reception of the eight bits of data (See Figure 17).
The ISL22343 responds with an ACK after recognition of a
START condition followed by a valid Identification Byte, and
once again after successful receipt of an Address Byte. The
ISL22343 also responds with an ACK after receiving a Data
SDA OUTPUT FROM
SDA OUTPUT FROM
TRANSMITTER
SCL FROM
RECEIVER
SDA
SCL
MASTER
SIGNALS FROM
SIGNAL AT SDA
SIGNALS FROM
THE MASTER
THE SLAVE
14
START
FIGURE 16. VALID DATA CHANGES, START AND STOP CONDITIONS
START
FIGURE 17. ACKNOWLEDGE RESPONSE FROM RECEIVER
HIGH IMPEDANCE
S
A
R
T
T
1
FIGURE 18. BYTE WRITE SEQUENCE
IDENTIFICATION
0
1
1
BYTE
0
A2
STABLE
DATA
A1
ISL22343
A0
WRITE
0
A
C
K
CHANGE
DATA
0 0 0 0
ADDRESS
Byte of a write operation. The master must respond with an
ACK after receiving a Data Byte of a read operation
A valid Identification Byte contains 1010 as four MSBs, and
the following three bits matching the logic values present at
pins A2, A1 and A0. The LSB is the Read/Write bit. Its value
is “1” for a Read operation and “0” for a Write operation (See
Table 3).
(MSB)
BYTE
0
1
STABLE
DATA
LOGIC VALUES AT PINS A2, A1 AND A0, RESPECTIVELY
TABLE 3. IDENTIFICATION BYTE FORMAT
0
A
C
K
8
1
DATA
BYTE
0
HIGH IMPEDANCE
STOP
ACK
9
A2
A
C
K
S
T
O
P
A1
A0
May 31, 2007
FN6423.0
(LSB)
R/W