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Development Tools User’s Manual
IXP2400/IXP2800 Network Processors
Developer Workbench
Register History:
To go along with the thread history, the Workbench will record register history. The values for all
GPRs, transfer registers and neighbor registers in each Microengine will be remembered for the
same cycle extents as thread history. The information displayed in a thread window datatip (the
“pop-up” window described in the previous section) for a register or a C variable will be based on
the register’s value at the cycle that is currently active in the history window. Similarly, a data
watch for a register or a C variable that is stored in a register will display the register’s value at the
active cycle. The active cycle can be changed by
•
Clicking on the left or right arrows in the history window or data watch window.
•
Dragging the cycle marker to the desired cycle count.
•
Double-clicking in the history window at the desired cycle count.
•
Right-clicking in the history window and selecting
Go To Instruction
from the context menu
Whenever simulation stops the active cycle is automatically set to be the most recently simulated
cycle. This means that datatips and data watches will display the current register values. The
history PC marker in all thread windows is hidden at this time.
When the active cycle is changed a non-current cycle, data watches and datatips of non-register
states and variables will display an appropriate message to indicate that the historical value is not
available.
2.13.12
Data Watch
In debug mode, you can monitor the values of simulation states using the
Data Watch
window.
To do this:
•
On the
View
menu, click
Debug Windows
, then click
Data Watch
, or
Click the
button on the
View
toolbar.
This toggles visibility of
the
Data Watch
window. The window
contains a list with three
columns:
Name
Contains the name
of the state being watched.
Value
Displays the state’s value.
Description
Contains information such as which chip, Microengine or thread the
watch pertains to.
Note:
GPR names cannot be entered directly into the data watch window.
Values Updates:
Watch values are updated whenever microcode execution stops. To force updating the values at
other times, click
Refresh
.