National Instruments AT-MIO-16X - page 218

Chapter 6 Calibration Procedures
AT-MIO-16X User Manual 6-6
© National Instruments Corporation
Figure 6-4. ADC and DAC FIFO Depth Field
If the ADC and DAC FIFO Depth Field contains the binary va lue
00010011, then the AT-MIO-16X board that was accessed c ontai ns an
ADC FIFO buffer of depth 512 and a DAC FIFO buffer of depth 2,0 48.
This information is extremely useful in determining how many values
to read from the ADC FIFO or write to the DAC FIFO when a half-full
interrupt is generated. For example, if it is known that the ADC FIFO is
512 values deep and a half-full interrupt is generated, then 25 6 va lues
can be read in at once without checking the Status Register 0 to see if
the FIFO contains values. Alternately, if the DAC FIFO is 2,048 values
deep and a half-full interrupt is generated, then 1,024 values can be
read. This can have a significant performance impact on software speed.
Figure 6-5. Area Information Field
If the Area Information Field contains the binary value XXXXX101
where X indicates don’t care bits, then the area described by this area
information value contains bipolar DAC 1 calibration constants,
unipolar DAC 0 calibration constants, and bipolar ADC calibration
constants. The area information value for the factory bipolar area will
always be XXXXX111, and for the factory unipolar area it will always
012
73456
ADC FIFO Length DAC FIFO Length
LSBMSB
0110 = 16,384
0010 = 1,024
0001 = 512
0000 = 256
0101 = 8,192
0100 = 4,096
0011 = 2,048
0
110 = 16,384
0
010 = 1,024
0
001 = 512
0
000 = 256
0
101 = 8,192
0
100 = 4,096
0
011 = 2,048
01273456
Reserved
Reserved
Reserved
Reserved
Reserved
DAC 1 Range
DAC 0 Range
ADC Range
LSBMSB