Functional Description and Application Information
S12S Debug (S12SDBGV1) Module
MM912F634
Freescale Semiconductor
219
4.31.3.2.3
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.
2–0
SSF[2:0]
State Sequencer Flag Bits — The SSF bits indicate in which state the State Sequencer is in currently. 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 state 0 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 265. 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 266. Debug Trace Control Register (DBGTCR)
Address: 0x0022
7
6
5
432
10
R0
TSOURCE
00
TRCMOD
0
TALIGN
W
Reset
0
000
00
0
Table 267. DBGTCR Field Descriptions
Field
Description
6
TSOURCE
Trace Source Control Bit — The TSOURCE bit enables a tracing session given a trigger condition. If the MCU 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
3–2
TRCMOD
flow information is stored. In Loop1 mode, change of flow information is stored but redundant entries into trace memory are
inhibited. In Detail mode, address and data for all memory and register accesses is stored. In Pure PC mode the program
counter value for each instruction executed is stored. See
Table 268.
0
TALIGN
Trigger Align Bit — This bit controls whether the trigger is aligned to the beginning or end of a tracing session.
0 Trigger at end of stored data
1 Trigger before storing data
Table 268. TRCMOD Trace Mode Bit Encoding
TRCMOD
Description
00
Normal
Table 264. DBGSR Field Descriptions (continued)
Field
Description