Atec Agilent-346a - Manual (Page 15)

15
Designing and Probing with Target Connections
Normal-Density, Medium-Performance Applications
In some cases, you may not have
a standard QFP package on the
target available for probing
access, or your device may be
available only in BGA packaging.
Agilent recommends that targets
with probing constraints have
connectors designed into the
prototype versions of the product
for effective hardware and soft-
ware debug. The following should
be considered when designing
with connectors:
• Select the appropriate connec-
tor technology for your target
speed and target density.
• Carefully select all lines for
routing to the connectors that
may be needed for debug.
• Group the lines at each
connector for your probing
convenience. For example,
Agilent may have written an
inverse assembler for your
device that has a preconfig-
ured signal order. Before
designing, refer to the docu-
mentation for this inverse
assembler for essential signal
lines and order.
• Keep the routing to connectors
as short as possible to mini-
mize target impact and provide
accurate data.
• Examine the impact of probing
isolation networks designed
into the target vs. the isolation
network products offered by
Agilent Technologies.
An isolation network must be
located between the target and
the logic analyzer. It can be
located on the target board in
through-hole or SMT parts; or
it can be attached to the logic
analyzer cable with the probe
leads (the isolation network is
molded into the end of the probe);
or the Agilent 01650-63203 isola-
tion adapter with self contained
isolation networks can be used.
Probe leads can be used with
connectors but are not the most
convenient method. Direct con-
nection of the connectors with
the analyzer cable (isolation net-
work parts on the target) or with
a probe or isolation adapter is the
faster, more convenient method.