ADC121C021CIMKX NSC [National Semiconductor], ADC121C021CIMKX Datasheet - Page 23

• Manufacturer Part Number: ADC121C021CIMKX
• Description: I2C-Compatible, 12-Bit Analog-to-Digital Converter (ADC) with Alert Function
• Manufacturer: NSC [National Semiconductor]

1.10 COMMUNICATING WITH THE ADC121C021
The ADC121C021's data registers are selected by the ad-
dress pointer (see Section 1.6.1). To read/write a specific data
register, the pointer must be set to that register's address. The
pointer is always written at the beginning of a write operation.
When the pointer needs to be updated for a read cycle, a write
1.10.1 Reading from a 2-Byte ADC Register
FIGURE 12. (b) Typical Pointer Set Followed by Immediate Read of a 2-Byte ADC Register
FIGURE 11. (a) Typical Read from a 2-Byte ADC Register with Preset Pointer
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operation must preceed the read operation to set the pointer
address correctly. On the other hand, if the pointer is preset
correctly, a read operation can occur without writing the ad-
dress pointer register. The following timing diagrams describe
the various read and write operations supported by the ADC.
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