Start convert register – National Instruments Low-Cost Multifunction I/O Board for ISA Lab-PC+ User Manual

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Appendix D

Register Map and Descriptions

© National Instruments Corporation

D-19

Lab-PC+ User Manual

Start Convert Register

Writing to the Start Convert Register location initiates an A/D conversion.

Address:

Base address + 03 (hex)

Type:

Write-only

Word Size:

8-bit

Bit Map:

Not applicable, no bits used

Note: A/D conversions can be initiated in one of two ways: by writing to the Start Convert

Register or by detecting an active low signal on either the Counter A0 output or the
EXTCONV* signal. If the Start Convert Register is to initiate an A/D conversion, the
Counter A0 output should be initialized to high state, which must be followed by an
ADCLEAR operation, by writing to the ADCLEAR Register.