adc128d818cimtx National Semiconductor Corporation, adc128d818cimtx Datasheet - Page 16

• Manufacturer Part Number: adc128d818cimtx
• Description: 12-bit, 8-channel, Adc System Monitor With Temperature Sensor, Internal/external Reference, And I2c Interface
• Manufacturer: National Semiconductor Corporation

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15.7 INTERFACE
The Serial Bus control lines include the SDA (serial data),
SCL (serial clock), and A0-A1 (Serial Bus Address) pins. The
ADC128D818 can only operate as a slave. The SCL line only
controls the serial interface, and all of other clock functions
within ADC128D818 are done with a separate asynchronous
internal clock.
When the Serial Bus Interface is used, a write will always
consists of the ADC128D818 Serial Bus Address byte, fol-
lowed by the Register Address byte, then the Data byte.
Figure 6
to the ADC128D818.
There are two cases for a read:
1.
2.
The Serial Bus Address can be found in the next section, and
the Register Address can be found in the "Register Map" sec-
tion. For more information on the I
"I
15.7.1 Serial Bus Address
There are nine different configurations for the ADC128D818
Serial Bus Address, thus nine devices are allowed on a single
15.7.3 Example Writes and Reads
2
C-Bus Specification and User Manual", rev. 03.
If the Register Address is known to be at the desired
address, simply read the ADC128D818 with the Serial
Bus Address byte, followed by the Data byte read from
the ADC128D818. Examples of this type of read can be
seen in
If the Register Address value is unknown, write to the
ADC128D818 with the Serial Bus Address byte, followed
by the desired Register Address byte. Then restart the
Serial Communication with a Read consisting of the
Serial Bus Address byte, followed by the Data byte read
from the ADC128D818. See
examples of this type of read.
and
Figure 8
Figure 7
FIGURE 6. Serial Bus Interface Write Example 1 - Internal Address Register Set Only.
and
are two examples showing how to write
Figure
9.
Figure 10
2
C Interface, refer to NXP's
and
Figure 11
for
16
I
midscale can be found in the "Example Applications" section.
The Serial Bus Address can be set as follows:
15.7.2 Timeout
The ADC128D818 I
either SCL or SDA is held low for longer than 35ms. This fea-
ture also ensures that ADC128D818 will automatically re-
lease SDA after driving it low continuously for 25-35ms, hence
preventing I
be used when the device is operating in deep shutdown
mode.
2
C bus. Examples to set each address bit low, high, or to
HIGH
HIGH
HIGH
LOW
LOW
LOW
MID
MID
MID
A1
TABLE 5. Serial Bus Address Table
2
C bus lock-up. The TIMEOUT feature should not
HIGH
HIGH
HIGH
LOW
LOW
LOW
MID
MID
MID
A0
2
C state machine resets to its idle state if
[A6][A5][A4]...[A0]
001_1101b
001_1110b
001_1111b
010_1101b
010_1110b
010_1111b
011_0101b
011_0110b
011_0111b
Serial Bus
Address
Address (hex)
Serial Bus
1Dh
1Eh
2Dh
2Eh
1Fh
2Fh
35h
36h
37h
30096309