Chapter 3
Analog Output Timing/Control
©
National Instruments Corporation
3-17
DAQ-STC Technical Reference Manual
AOFFF*
IU
Data FIFO Full Flag—This input is used to generate the FIFO
interrupt and the FIFO request signal (AOFREQ) based on the
status of the FIFO. The input polarity is selectable, and the input
state can be directly observed in one of the status registers.
Source: AO data FIFO. Related bitfields:
AO_FIFO_Flags_Polarity, AO_FIFO_Full_St.
AOFHF*
IU
Data FIFO Half-full Flag—This input is used to generate the
FIFO interrupt and the FIFO request signal (AOFREQ) based on
the status of the FIFO. The input polarity is selectable, and the
input state can be directly observed in one of the status registers.
Source: AO data FIFO. Related bitfields:
AO_FIFO_Flags_Polarity, AO_FIFO_Half_Full_St.
AOFFRT*
O4TU
Data FIFO Retransmit—This active low output instructs the data
FIFO to retransmit its contents. It is used primarily in the local
buffer mode. When enabled, AOFFRT pulses each time AOFEF
indicates a FIFO empty condition. Destination: AO data FIFO.
Related bitfields: AO_FIFO_Retransmit_Enable.
AOFREQ
O9TU
Data FIFO Request—This output is a FIFO request signal that
indicates that the data FIFO needs to be loaded with output data.
The AOFREQ signal is generated directly from the data FIFO
status flags—AOFEF, AOFHF, and AOFFF. The AOFREQ
generation conditions are: assert on empty FIFO; assert on
half-full or less FIFO; assert on less than full FIFO; assert on
half-full or less FIFO, deassert on full FIFO. Output polarity is
selectable. Destination: DMA Controller or CPU. Related
bitfields: AO_AOFREQ_Polarity, AO_AOFREQ_Enable,
AO_FIFO_Mode.
BC_TC
O4TU
The BC Counter Terminal Count Signal—Output polarity is
active high. Related bitfields:
Misc_Counter_TCs_Output_Enable.
Table 3-1.
Pin Interface (Continued)
Pin Name
Type
Description
