MC9S12XD256MAL Datasheet, PDF (782/1348 Pages) Freescale Semiconductor, Inc – Freescale’s Scalable Controller Area Network

Chapter 20 S12X Debug (S12XDBGV3) Module
upon the state of the DBGBRK or ARM bits in DBGC1. They depend solely on the state of the XGSBPE
and BDM bits. Thus it is not necessary to ARM the DBG module to use XGATE software breakpoints to
generate breakpoints in the S12XCPU program flow, but it is necessary to set XGSBPE. Furthermore, if a
breakpoint to BDM is required, the BDM bit must also be set. When the XGATE requests an S12XCPU
breakpoint, the XGATE program flow stops by default, independent of the S12XDBG module.
20.4.7.2 Breakpoints From Internal Comparator Channel Final State Triggers
Breakpoints can be generated when internal comparator channels trigger the state sequencer to the Final
State. If configured for tagging, then the breakpoint is generated when the tagged opcode reaches the
execution stage of the instruction queue.
If a tracing session is selected by the TSOURCE bits, breakpoints are requested 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 (see Table 20-44). If no tracing session is selected, breakpoints are
requested immediately.
If the BRK bit is set on the triggering channel, then the breakpoint is generated immediately independent
of tracing trigger alignment.
Table 20-44. Breakpoint Setup For Both XGATE and S12XCPU Breakpoints
BRK
0
0
0
0
0
0
1
1
x
TALIGN
00
00
01
01
10
10
00,01,10
00,01,10
11
DBGBRK[n]
0
1
0
1
0
1
1
0
x
Breakpoint Alignment
Fill Trace Buffer until trigger
(no breakpoints — keep running)
Fill Trace Buffer until trigger, then breakpoint request occurs
Start Trace Buffer at trigger
(no breakpoints — keep running)
Start Trace Buffer at trigger
A breakpoint request occurs when Trace Buffer is full
Store a further 32 Trace Buffer line entries after trigger
(no breakpoints — keep running)
Store a further 32 Trace Buffer line entries after trigger
Request breakpoint after the 32 further Trace Buffer entries
Terminate tracing and generate breakpoint immediately on trigger
Terminate tracing immediately on trigger
Reserved
20.4.7.3 Breakpoints Generated Via The TRIG Bit
If a TRIG triggers occur, the Final State is entered. Tracing trigger alignment is defined by the TALIGN
bits. If a tracing session is selected by the TSOURCE bits, breakpoints are requested 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 (see Table 20-44). If no tracing session is selected, breakpoints are
requested immediately. TRIG breakpoints are possible even if the S12XDBG module is disarmed.
MC9S12XDP512 Data Sheet, Rev. 2.21
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