Chapter 20 Debug (S12XDBGV2)
MC9S12XDP512 Data Sheet, Rev. 2.11
798 Freescale Semiconductor
20.3.1.2 Debug Status Register (DBGSR)
Read: Anytime

Write: Never

01 Comparator B DBGSCR2
10 Comparator C DBGSCR3
11 Comparator D DBGSCR3
0x0021
76543210
R TBF EXTF 0 0 0 SSF2 SSF1 SSF0
W
Reset 0 0 0 0000
POR00000000
Unimplemented or Reserved

Figure 20-4. Debug Status Register (DBGSR)

Table 20-6. DBGSR Field Descriptions

Field Description
7
TBF
Trace Buffer Full — The TBF bit indicates that the trace buffer has stored 64 or more lines of data since it was
last armed. If this bit is set, then all 64 lines will be valid data, regardless of the value of DBGCNT bits CNT[6:0].
The TBF bit is cleared when ARM in DBGC1 is written to a 1. The TBF is cleared by the power on reset
initialization. Other system generated resets have no affect on this bit
6
EXTF
External Tag Hit Flag — The EXTF bit indicates if a tag hit condition from an external TAGHI/TAGLO tag was
met since arming. This bit is cleared when ARM in DBGC1 is written to a 1.
0 External tag hit has not occurred
1 External tag hit has occurred
2–0
SSF[2:0}
State Sequencer Flag Bits — The SSF bits indicate in which state the state sequencer is currently in. During
a debug session on each transition to a new state these bits are updated. If the debug session is ended by
software clearing the ARM bit, then these bits retain their value to reflect the last state of the state sequencer
before disarming. If a debug session is ended by a breakpoint, then the state sequencer returns to state0 and
these bits are cleared to indicate that state0 was entered during the session. On arming the module the state
sequencer enters state1 and these bits are forced to SSF[2:0] = 001. See Table 20-7.

Table 20-7. SSF[2:0] — State Sequence Flag Bit Encoding

SSF[2:0] Current State
000 State0 (disarmed)
001 State1
010 State2
011 State3
100 Final State
101,110,111 Reserved

Table 20-5. COMRV Encoding

COMRV Visible Comparator Visible State Control Register