National Instruments AT-MIO-16X User Manual

Page 107

Chapter 4

4-11

AT-MIO-16X User Manual

EXTREFDAC1 External Reference for DAC 1—This bit

controls the reference selection for DAC
1 in the analog output section. If this bit
is set, the reference used for DAC 1 is the
external reference voltage from the I/O
connector. If this bit is cleared, the
internal +10 V

ref

is used for the DAC 1

reference.

EXTREFDAC0 External Reference for DAC 0—This bit

controls the reference selection for
DAC 0 in the analog output section. If
this bit is set, the reference used for DAC
0 is the external reference voltage from
the I/O connector. If this bit is cleared,
the internal +10 V

ref

is used for the DAC

0 reference.

EISA_DMA

EISA Computer DMA—This bit controls
the type of DMA transfer from the ADC
FIFO on an EISA computer. If
EISA_DMA is clear, single transfer
DMA mode is used. If EISA_DMA is set,
demand-mode DMA is used. This bit
should only be set if the AT-MIO-16X is
installed in an EISA-type computer.

Reserved—This bit must always be set to
zero.

5-3

DMACHBB<2..0>

DMA Channel B Select—These bits
select the secondary DMA channel for
use by the AT-MIO-16X. See Table 4-2.

2-0

DMACHAB<2..0>

DMA Channel A Select—These bits
select the primary DMA channel for use
by the AT-MIO-16X. See Table 4-2.