Reset Generation; Analog Input Interface - Analog Devices ADSP-21992 EZ-KIT LITE System Manual

System Architecture

Reset Generation

The ADSP-21992 can be reset from a number of sources on the
ADSP-21992 EZ-KIT Lite board. The sources of reset for the
ADSP-21992 DSP are:
• POR (power-on reset output pin of the ADSP-21992)
• Reset button (
• External power on reset IC (
• USB Interface (software tools reset)
Choose the source of reset for the ADSP-21992 by configuring jumper
. When
JP2 JP2
ADSP-21992 is tied to the reset pin of the ADSP-21992. When
the 1-2 position, the source of reset for the ADSP-21992 is the reset but-
ton ( ), the external power-on reset IC (ADM708), or a reset command
S1
from VisualDSP++ through the USB interface. Position 1-2 (default) is
recommended when using the VisualDSP++ development tools.

Analog Input Interface

The ADSP-21992 EZ-KIT Lite board permits up to eight analog inputs to
be fed from the analog inputs connector (
of the ADSP-21992. All eight analog inputs at the analog inputs connec-
tor may range from -1V to +1V.
There is a separate interface circuit for each of the eight ADC channels of
the ADSP-21992. These analog interface circuits convert the nominal
±1V signals at the analog inputs connector
ADSP-21992 reference voltage level (either the internally derived 1.0V
level or the externally provided 1.024V level). The analog interface cir-
cuits, consisting of high-performance operational amplifiers and precision
resistors, effectively offset the analog inputs by the reference voltage level.
3-4
)
S1
is in the 2-3 position, the
ADSP-21992 EZ-KIT Lite Evaluation System Manual
)
A7
output pin of the
POR
) to the eight ADC channels
P4
to signals centered on the
P4
is in
JP2