National Instruments Low-Cost Multifunction I/O Board for ISA..., User Manual

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Register Map and Descriptions Appendix D
Lab-PC+ User Manual D-4 © National Instruments Corporation
Configuration and Status Register Group
The five registers making up the Configuration and Status Register Group allow general control
and monitoring of the Lab-PC+ A/D and D/A circuitry. Command Register 1 and Command
Register 2 contain bits that control the operation modes of the A/D and D/A circuitry. Command
Register 3 enables or disables the interrupt and DMA operations. Command Register 4 is used to
select the analog input mode, and also allows certain analog input conversion signals to be
externally driven or received at the I/O connector. The Status Register reports the status of the
A/D conversion, A/D conversion error, and the status of the interrupts. When you start up your
PC, all bits of the Command Registers are cleared.
Bit descriptions for the registers in the Configuration and Status Register Group are given on the
following pages.