SP43503 Datasheet, PDF (8/10 Pages) SIPAT Co,Ltd – SP43503

Evaluation Kit
The Digital Attenuator Evaluation Kit board was
designed to ease customer evaluation of the
SP43503 Digital Step Attenuator.
Direct-Parallel Programming Procedure
For automated direct-parallel programming,
connect the test harness provided with the EVK
from the parallel port of the PC to the J1 & Serial
header pin and set the D0-D6 SP3T switches to
the ‘MIDDLE’ toggle position. Position the
Parallel/Serial (P/̅ S) select switch to the Parallel
(or left) position. The evaluation software is
written to operate the DSA in either Parallel or
Serial-Addressable Mode. Ensure that the
software is set to program in Direct-Parallel mode.
Using the software, enable or disable each setting
to the desired attenuation state. The software
automatically programs the DSA each time an
attenuation state is enabled or disabled.
For manual direct-parallel programming,
disconnect the test harness provided with the EVK
from the J1 and Serial header pins. Position the
Parallel/Serial (P/̅ S) select switch to the Parallel
(or left) position. The LE pin on the Serial header
must be tied to V_DD. Switches D0-D6 are SP3T
switches which enable the user to manually
program the parallel bits. When any input D0-D6
is toggled ‘UP’, logic high is presented to the
parallel input. When toggled ‘DOWN’, logic low is
presented to the parallel input. Setting D0-D6 to
the ‘MIDDLE’ toggle position presents an OPEN,
which forces an on-chip logic low. Table 9 depicts
the parallel programming truth table and Fig. 16
illustrates the parallel programming timing
diagram.
Latched-Parallel Programming Procedure
For automated latched-parallel programming, the
procedure is identical to the direct-parallel
method. The user only must ensure that Latched-
Parallel is selected in the software.
For manual latched-parallel programming, the
procedure is identical to direct-parallel except now
the LE pin on the Serial header must be logic low
SP43503
Product Specification
Figure 17. Evaluation Board Layout
Note: Reference Figure 18 for Evaluation Board Schematic
as the parallel bits are applied. The user must
then pulse LE from 0V to V_DD and back to 0V to
latch the programming word into the DSA. LE
must be logic low prior to programming the next
word.
Serial Programming Procedure
Position the Parallel/Serial (P/̅ S) select switch to
the Serial (or right) position. The evaluation
software is written to operate the DSA in either
Parallel or Serial Mode. Ensure that the software
is set to program in Serial mode. Using the
software, enable or disable each setting to the
desired attenuation state. The software
automatically programs the DSA each time an
attenuation state is enabled or disabled.
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