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Chapter 3
Register Map and Descriptions
3-16
©
National Instruments Corporation
AO Configuration Register
The AO Configuration Register contains five bits that control the PCI E Series analog output
configuration. The contents of this register are cleared upon power up and after a reset
condition.
Address:
Base a 16 (hex)
Type:
Write-only
Word Size:
16-bit
Bit Map:
Bit
Name
Description
15–9,
Reserved
Reserved—Always write 0 to these bits.
7–4
8
DACSel
DAC Select—This bit indicates which DAC is the
destination for the configuration bits in this register.
DAC0 will be selected when this bit is cleared, and DAC1
will be selected when set.
3
GroundRef
Ground Reference—This bit connects the reference for
both DACs to ground when this bit is set. This is useful for
calibration of the DAC linearity. This bit is not currently
implemented as a separate selection for the two DACs.
Therefore, its state is determined by the last value
written to this bit field. This bit is reserved on the
PCI-MIO-16XE-50, PCI-MIO-16XE-10, and PCI-6031E.
It should be set to 0.
2
ExtRef
External Reference for DAC—This bit controls the
reference selection for the selected DAC. If this bit is set,
the reference used for the DAC is the external reference
voltage from the I/O connector. If this bit is cleared, the
in10 V
ref
is used for the DAC reference. This bit is
reserved on the PCI-MIO-16XE-50, PCI-MIO-16XE-10,
15
14
13
12
11
10
9
8
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
DACSel
7
6
5
4
3
2
1
0
Reserved
Reserved
Reserved
Reserved
GroundRef
ExtRef
ReGlitch
BipDac