JYTEK NuDAQ PCI-69222, User Manual

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Operation Theory 57
Figure 4-28: Digital Waveform Acquisition Operation
Digital Waveform Generation
The digital output on GPO [15..0] channels can be updated by
using digital waveform generation mode. This works similar to
AO waveform generation. With periodic update clock, you can
generate a sequence of digital output patterns based on
precision hardware time interval. The PCI-69222 and PCI-
69223 come with a dedicated FIFO that stores these waveform
patterns. The update patterns are transferred from the system
memory to the FIFO via DMA after the digital waveform
generation starts.
The GPO update clock source can be configured from the
onboard timer pacer, internal analog conversion clock, or
external clock. When using the internal timer pacer as update
clock source, the GPO supports data update rates of up to
2MHz.
The internal analog conversion clock source can come from AI
conversion clock or AO update clock, while the external signal
clock source can be set from any of the GPI [0..7] pins. When
the update clock is from the GPI and the GPI funtions at the
same time, the actual GPI data width is only 15-bit. Figure 4-29
illustrates the routing of GPO update clock.
Figure 4-29: Digital Waveform Generation Operation
CN
2
S
C
S
I CO
N
N
E
CT
O
R
GP
O
[1
5
..
0
]
GPO
Sa
m
p
le
cl
o
ck
sel
ect
AI Conversion Clock
GPO
Waveform
FIFO
Internal Divided Down Timer
GPI[7..0]
AO Update Clock
GPO Sample Clock
Static GPO
GPTC Output