Datasheet

S12S Debug Module (S12SDBGV2)
MC9S12G Family Reference Manual, Rev.1.23
Freescale Semiconductor 321
8.3.2.5 Debug Trace Buffer Register (DBGTBH:DBGTBL)
Read: Only when unlocked AND unsecured AND not armed AND TSOURCE set.
Write: Aligned word writes when disarmed unlock the trace buffer for reading but do not affect trace buffer
contents.
8.3.2.6 Debug Count Register (DBGCNT)
Table 8-10. ABCM Encoding
ABCM Description
00 Match0 mapped to comparator A match: Match1 mapped to comparator B match.
01 Match 0 mapped to comparator A/B inside range: Match1 disabled.
10 Match 0 mapped to comparator A/B outside range: Match1 disabled.
11 Reserved
1
1
Currently defaults to Comparator A, Comparator B disabled
Address: 0x0024, 0x0025
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
W
PORXXXXXXXXXXXXXXXX
Other
Resets
————————————————
Figure 8-7. Debug Trace Buffer Register (DBGTB)
Table 8-11. DBGTB Field Descriptions
Field Description
15–0
Bit[15:0]
Trace Buffer Data Bits — The Trace Buffer Register is a window through which the 20-bit wide data lines of the
Trace Buffer may be read 16 bits at a time. Each valid read of DBGTB increments an internal trace buffer pointer
which points to the next address to be read. When the ARM bit is set the trace buffer is locked to prevent reading.
The trace buffer can only be unlocked for reading by writing to DBGTB with an aligned word write when the
module is disarmed. The DBGTB register can be read only as an aligned word, any byte reads or misaligned
access of these registers return 0 and do not cause the trace buffer pointer to increment to the next trace buffer
address. Similarly reads while the debugger is armed or with the TSOURCE bit clear, return 0 and do not affect
the trace buffer pointer. The POR state is undefined. Other resets do not affect the trace buffer contents.
Address: 0x0026
76543210
R TBF 0 CNT
W
Reset
POR
—
0
—
0
—
0
—
0
—
0
—
0
—
0
—
0
= Unimplemented or Reserved
Figure 8-8. Debug Count Register (DBGCNT)