Measurement Computing PCM-DAS16x/16 - Manual (Page 33)

9 I/O ADDRESS MAP & REGISTER FUNCTIONS
A base address register controls the beginning, or 'Base Address' of the I/O addresses
occupied by the control registers of the PCM-DAS16x/16. In all, 16 addresses are
occupied. The base address assigned by CSS read by InstaCAL and stored in the
CB.CFG file installed in your computer. Please read about installing and using Insta-
CAL.
9.1 CONTROL REGISTERS
Once CSS is installed and a base address has been established, the PCM-DAS16x/16
may be controlled by writing to and reading from the control registers. While it is
possible to write your own control routines for the PCM-DAS16x/16, routines have
been written and are available in ComputerBoards' Universal Library for DOS and
Windows programming languages.
NOTE ON REGISTER PROGRAMMING SUPPORT
While the complete register map is explained here, only very limited support for
assembly language or direct register programming is available. Register level pro-
gramming should only be attempted by experieced programmers. We support the use
of the PCM-D24/CTR3 through high level languages using UniversalLibrary and the
expample programs provided.
Major functions of the control registers:
I/O ADDRESS PCM-DAS16x/16 FUNCTION R | W
BASE + 0 A/D Data & Channel | Start A/D
BASE + 2 Digital In|Out & Channel Scan Limits
BASE + 4 Interrupt Control & Status
BASE + 6 Input Range and Trigger Method
BASE + 8 Counter 0 Read | Load
BASE + A Counter 1 Read | Load
BASE + C Counter 2 Read | Load
BASE + E None | Counter Control
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