Chapter 6 S12Z Debug (S12ZDBGV2) Module
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
226
Freescale Semiconductor
6.4.7
Breakpoints
Breakpoints can be generated by state sequencer transitions to State0. Transitions to State0 are forced by
the following events
•
Through comparator matches via Final State.
•
Through software writing to the TRIG bit in the DBGC1 register via Final State.
•
Through the external event input (DBGEEV) via Final State.
•
Through a profiling trace buffer overflow event.
Breakpoints are not generated by software writes to DBGC1 that clear the ARM bit.
6.4.7.1
Breakpoints From Comparator Matches or External Events
Breakpoints can be generated when the state sequencer transitions to State0 following a comparator match
or an external event.
If a tracing session is selected by TSOURCE, the transition to State0 occurs when the tracing session has
completed, thus if Begin or Mid aligned triggering is selected, the breakpoint is requested only on
completion of the subsequent trace. If End aligned tracing or no tracing session is selected, the transition
to State0 and associated breakpoints are immediate.
6.4.7.2
Breakpoints Generated Via The TRIG Bit
When TRIG is written to “1”, the Final State is entered. If a tracing session is selected by TSOURCE,
State0 is entered and breakpoints are requested only when the tracing session has completed, thus if Begin
or Mid aligned triggering is selected, the breakpoint is requested only on completion of the subsequent
trace. If no tracing session is selected, the state sequencer enters State0 immediately and breakpoints are
requested. TRIG breakpoints are possible even if the DBG module is disarmed.
6.4.7.3
DBG Breakpoint Priorities
If a TRIG occurs after Begin or Mid aligned tracing has already been triggered by a comparator instigated
transition to Final State, then TRIG no longer has an effect. When the associated tracing session is
complete, the breakpoint occurs. Similarly if a TRIG is followed by a subsequent comparator match, it has
no effect, since tracing has already started.
Line
Byte4
Byte3
Byte2
Byte1
Line0
1 0 0 1 0 0 1 0 0 1 0 1 1 0 0 1 0 0 1 0 0 0 0 1 1 0 0 0 0 1 1 0
Line1
0 1 1 0 0 1 0 1 1 0 0 1 0 0 1 0 1 1 0 0 1 0 0 1 0 1 1 0 0 1 0 0
Line2
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 1
Table 6-60. Profiling Direct COF Format
