DAC0830/DAC0832
DAC0830 Series Application Hints
(Continued)
00560835
*
TIE TO LOGIC 1 IF NOT NEEDED (SEE SEC. 1.1).
FIGURE 2. Controlling Mutiple DACs
00560836
FIGURE 3.
The ILE pin is an active high chip select which can be
decoded from the address bus as a qualifier for the normal
CS signal generated during a write operation. This can be
used to provide a higher degree of decoding unique control
signals for a particular DAC, and thereby create a more
efficient addressing scheme.
Another useful application of the ILE pin of each DAC in a
multiple DAC system is to tie these inputs together and use
this as a control line that can effectively “freeze” the outputs
of all the DAC’s at their present value. Pulling this line low
latches the input register and prevents new data from being
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written to the DAC. This can be particularly useful in multi-
processing systems to allow a processor other than the one
controlling the DAC’s to take over control of the data bus and
control lines. If this second system were to use the same
addresses as those decoded for DAC control (but for a
different purpose) the ILE function would prevent the DAC’s
from being erroneously altered.
In a “Stand-Alone” system the control signals are generated
by discrete logic. In this case double-buffering can be con-
trolled by simply taking CS and XFER to a logic “0”, ILE to a
logic “1” and pulling WR
1
low to load data to the input latch.
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