Chapter
2 Register
Map and Descriptions
©
National Instruments Corporation
2-19
Static DIO Register-Level Programmer Manual
Automatic Clock Selection Register (PXI-6528 Only)
This register enables/disables automatic clock selection (selecting between the PXI 10 MHz
backplane clock and the 10 MHz onboard oscillator), and gives which clock is currently being
used.
Address Offset:
0x14
Type:
Bit 0: Write-only
Bit 1: Read-only
Size:
8-bit
Bit Map:
Bit
Name
Description
7–2
Reserved
Write only zeros to these bits.
1
SystemClockStatus
Bit 1 indicates which clock is currently being
used as the system clock (SClk). A 0 indicates
the PXI 10 MHz backplane clock is being used.
A 1 indicates the 10 MHz onboard oscillator is
being used.
0
AutomaticClockDisable
Bit 0 has a default value of 0, which means
automatic clock selection is enabled. Write a 1 to
bit 0 to disable automatic clock selection and
force use of the onboard oscillator.
7
6
5
4
3
2
1
0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
SClkStat
AutoClkDis