National Instruments AT-MIO-16X - Manual (Page 148)

Chapter 4 Register Map and Descriptions
AT-MIO-16X User Manual 4-52 © National Instruments Corporation
ADC Calibration Register
Accessing the ADC Calibration Register location initiates an ADC
calibration procedure. This register should be strobed after power up to
assure the ADC is in a calibrated state.
Address: Base address + 1F (hex)
Type: Write-only
Word Size: 8-bit
Bit Map: Not applicable, no bits used
Strobe Effect: Initiates an ADC-level calibration (not a system-level
calibration)
Note: The ADC_BUSY* signal in Status Register 2 should be monitored to
determine when the AT-MIO-16X ADC calibration cycle is finished. The
calibration cycle takes approximately 1.25 sec to complete. All other
conversions must be inhibited until the ADC calibration cycle is completed.
After the calibration cycle, the ADC must be initialized by generating a
conversion. The Single Conversion Register should be accessed to start an
A/D conversion. After the conversion is completed, the result will be stored
in the ADC FIFO. Because this data is meaningless, it must be cleared by
reading the value from the FIFO or accessing the DAQ Clear Register.