Resource Terms - HP 1630A Operating And Programming Manual

Model 1630A/D/G
State Measurements
Resource Terms
When the logic analyzer takes state traces, activity is clocked into the analyzer by a clock from the target
system . After 1024 consecutive states have been stored, the trace halts and is displayed on the analyzer screen .
This method of taking traces is used in many cases, but usually a sequence of data or a particular event is of
interest, making need for qualification of data before it is captured . Resource terms are used to define specific
states for qualifying data before it is captured by the logic analyzer .
Resource terms may be defined with the logic analyzer, with which the analyzer compares incoming bit
patterns . Only activity complying with terms specified in the State Trace Specification is stored by the
analyzer . Four terms are available for use as resource terms: a, b, c, and d . The resource terms are user defined
and may be assigned for simple triggering, sequence triggering, sequence restart, and/or store qualifying .
TRIGGER [START/CENTER/END] TRACE
When a resource term is defined as the trigger term to [start]the state trace, the analyzer waits until the trigger
is found and then starts storing states in memory . After 1024 states have been stored, the trace is halted . The
captured state list is then displayed on the analyzer screen with the trigger term at line location 0000 in the
State Listing . Selective storing of states may be specified in the State Trace Specification bydefining terms to
be stored after the trigger is found .
When the resource term is defined as the trigger term to [center] the trace, the analyzer keeps track of the
trigger term in the same manner as a when a start trace term has been defined . After the trigger term is found
and identified as the center of trace, states previous to the triggerterm, the triggerterm and the next 511 states
are stored . The entire memory length of 1024 states may not always be listed in the State Listing. For instance,
if the trigger term is found at the tenth state after RUN is pressed, nine states will be listed before the trigger in
the listing (and labeled with a minus sign), the trigger (at line 0000), and 511 states after the trigger(labeled with
a plus sign). The total listing will be 521 states long . Additional resource terms may be defined for selective
storing .
The trace is stopped at the trigger term when the State Trace Specification defines the trigger term as the end
of the trace. The analyzer displays the trigger term and up to 1024 states previous to the trigger depending on
where the trigger is found after the RUN key is pressed . If the trigger term is found after 100 states, the State
Listing will consist of 101 states .
Up to 59,999 occurrences of a state may be specified in the occurrence field of the State Trace Specification in
order to pass loops in program activity that are well removed from the defined trigger term .
1 . Press RUN and select one of the addresses from the ADDR column in the State Listing .
2. Press TRACE. Move the cursor to the [any state] field and select resource term [a] by pressing the
NEXT[] key twice. When one or more resource terms have been selected,the four fields to define the
terms are automatically added to the State Trace Specification menu as shown in figure 4-22 .
3. Move the cursor to the first field under the ADDR label and type in the address selected in step 1 . This
specification tells the analyzer to start storing the trace in memory when it finds the selected address on
the lines that have been labeled ADDR . The X's in the other fields indicate that any value on those lines
will satisfy the trigger specification . Figure 4-23 is the trace specification to trigger on the first
occurrence of a specified address .
4. Press RUN . The analyzer will monitor activity from the system under test until it finds the condition
specified on the address lines . Then it captures that state in memory and all successive states until the
memory is filled one time . The message "Trace Complete" will be displayed after a trace has been
completed by the analyzer . The State Listing is shown in figure 4-24 .
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