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CHAPTER 2 DEPENDENCE FUNCTIONS
Figure 2.3-2 Frame Numbering at Tracing
■ Trace Filter
To make effective use of the limited trace buffer capacity, in addition to the code fetch function, a trace filter
function is incorporated to provide a means of acquiring information about data accesses to a specific region.
The data trace filter function allows the following values to be specified for two regions:
- Address
- Address mask
- Access attribute (read/write)
Another function can be used so that sampling of redundant frames occupying two or more trace frames, such
as SLEEP and READY, can be reduced to sampling of one frame.
■ Trace Trigger Setup
When preselected conditions are met during MCU bus operation monitoring, a trigger for starting a trace can
be generated. This function is called a trace trigger.
For the use of the trace trigger function, specify the code (/CODE) and data access (/READ/WRITE).
Up to 8 trace triggers can be preset each for code attribute and data access attribute. However, actually, the
maximum number of trace triggers is determined as indicated below because the common hardware is used
with events.
Current trace trigger maximum constant
= 8 - (current data monitoring break count setting + current event count setting)
For the trace trigger setup conditions that can be defined, see Table 2.3-4.
For trace trigger setup, use the following commands:
- SET TRACETRIGGER : Sets trace trigger
- CANCEL TRACETRIGGER : Deletes trace trigger
- SHOW TRACE/STATUS : Displays trace setup status
Figure 2.3-3 shows a trace sampling operation.
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-3
-2
-1
0 (Trigger point)