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Register-Based Programming 51
Appendix B
Appendix B
Register-Based Programming
About This Appendix
This appendix contains the information you can use for register-based
programming of the RF Multiplexers. The contents include:
•
Addressing the Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
•
Reading the Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
•
Writing to the Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
•
Selecting Channels Using Your Own Relays . . . . . . . . . . . . . .57
Addressing the Registers
The RF Multiplexer module is a register-based device. To read or write to
specific registers, you must use the command register address. Complete
command register address is determined by:
•
The address space (determined by the command module and
mainframe used)
•
The module address (determined by the command module used
and the module’s logical address switch)
•
The register offset (for the desired register).
Example: Addressing a Status/Control Register
This example shows how to address the Status/Control Register of an RF
Multiplexer module in a C-Size VXI mainframe using an E1406 Command
Module. Register addresses for modules are in address space VXI A16.
The location of A16 within the E1406 Command Module starts at (1F0000
h
)
(
h
= HEX).
The A16 space is divided so modules are addressed only at locations
beginning with C000
h
within A16. Allocated for each module are 64 register
addresses (40
h
). The module base address is related to the logical address
set by the module’s logical address switch (LADDR). The module address is:
module address
h
= (logical address
h
)* 40
h
+ C000
h
For the RF Multiplexer module, the default logical address is 120 (78 h),
so the module address within A16 = 78
h
* 40
h
+ C000
h
= DE00
h
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