S12S Debug Module (S12SDBGV2)
Read: Anytime
Write: Never
Table 6-5. DBGSR Field Descriptions
Description
Field
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. The TBF
bit is cleared when ARM in DBGC1 is written to a one. The TBF is cleared by the power on reset initialization.
Other system generated resets have no affect on this bit
This bit is also visible at DBGCNT[7]
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 an internal event, 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 6-6.
Table 6-6. SSF[2:0] — State Sequence Flag Bit Encoding
SSF[2:0]
000
Current State
State0 (disarmed)
State1
001
010
State2
011
State3
100
Final State
Reserved
101,110,111
6.3.2.3
Debug Trace Control Register (DBGTCR)
Address: 0x0022
7
6
5
4
3
2
1
0
R
W
0
0
0
0
0
TSOURCE
TRCMOD
TALIGN
Reset
0
0
0
0
0
0
0
Figure 6-5. Debug Trace Control Register (DBGTCR)
Read: Anytime
Write: Bit 6 only when DBG is neither secure nor armed.Bits 3,2,0 anytime the module is disarmed.
Table 6-7. DBGTCR Field Descriptions
Field
Description
6
Trace Source Control Bit — The TSOURCE bit enables a tracing session given a trigger condition. If the MCU
TSOURCE system is secured, this bit cannot be set and tracing is inhibited.
This bit must be set to read the trace buffer.
0 Debug session without tracing requested
1 Debug session with tracing requested
S12P-Family Reference Manual, Rev. 1.13
Freescale Semiconductor
161
FREESCALE [ Freescale ]
