Windowing Registers; Programming Examples - National Instruments PCI E Series Programmer's Manual

Windowing Registers

Programming Examples

© National Instruments Corporation
Since the DAQ-STC contains a large number of registers (180), eight
address lines would be required to decode the addresses in direct address
mode. In addition to the DAQ-STC registers, the PCI E Series boards
have other discrete registers. In order to retain compatibility with the AT
E Series boards, which have a limited address space, the PCI E Series
boards use the same windowing scheme for the DAQ-STC.
The windowing scheme allows a smaller address space requirement for
the DAQ-STC at the expense of requiring more accesses to perform the
same task. To write to a register in Windowed mode, write the address
offset to the Window_Address_Register. Write the bit pattern (data) to
the Window_Data_Write_Register. Similarly, to read from a register
in Windowed mode, write the address offset to the
Window_Address_Register; read from the Window_Data_Read_Register.
The programs presented in this chapter are broken into three sections:
Digital I/O, Analog Input, and Analog Output. Each example provides the
pseudo-code for the main program. The examples follow the procedure
presented in detail in the DAQ-STC Technical Reference Manual, and
further explanation of the functions are in this manual. Each program is
also provided in its entirety on the PCI E Series Register Level
Programmer Manual Companion Disk.
The Companion Disk also contains the support files necessary to run the
examples. The support files for the PC are under the PC directory on the
disk; the support files for the Macintosh are under the Mac directory, and
all of the examples are under the examples directory. Include all of the files
under the PC or Mac directory and the appropriate example file in your
project. In addition, Macintosh users should include the NI-DAQ library for
Macintosh as a shared library.
4-5
Chapter 4 Programming
PCI E Series RLPM