Reading more than three bytes from the ADS1100 has no
effect. All of the bytes beginning with the fourth will be FFH.
do this, address the ADS1100 for writing, and write one byte
to it. This byte is written into the configuration register.
A timing diagram for an ADS1100 read operation is shown in
Figure 2.
Writing more than one byte to the ADS1100 has no effect.
The ADS1100 will ignore any bytes sent to it after the first
one, and it will only acknowledge the first byte.
WRITING TO THE ADS1100
A timing diagram for an ADS1100 write operation is shown in
Figure 3.
You can write new contents into the configuration register
(you cannot change the contents of the output register). To
1
9
1
9
SCL
…
…
SDA
1
0
0
1
A2
A1
A0 R/W
D15 D14 D13 D12 D11 D10 D9
D8
Start By
Master
ACK By
ADS1100
From
ADS1100
ACK By
Master
Frame 1: I2C Slave Address Byte
Frame 2: Output Register Upper Byte
1
9
1
9
SCL
(Continued)
…
…
SDA
(Continued)
ST/
BSY
D7 D6
D5
D4
D3
D2
D1
D0
PGA1 PGA0
SC DR1 DR0
0
0
From
ADS1100
ACK By
Master
ACK By
Master
Stop By
Master
From
ADS1100
Frame 3: Output Register Lower Byte
Frame 4: Configuration Register
(Optional)
FIGURE 2. Timing Diagram for Reading From the ADS1100.
1
9
1
9
SCL
ST/
BSY
A2
PGA1 PGA0
SC DR1 DR0
SDA
1
0
0
1
A1
A0 R/W
0
0
Stop By
Master
Start By
Master
ACK By
ACK By
ADS1100
ADS1100
Frame 1: I2C Slave Address Byte
Frame 2: Configuration Register
FIGURE 3. Timing Diagram for Writing to the ADS1100.
ADS1100
11
SBAS239
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