MC9S12GRMV1 Datasheet, PDF (342/1292 Pages) Freescale Semiconductor, Inc – MC9S12G Family Reference Manual and Data Sheet

S12S Debug Module (S12SDBGV2)
Table 8-39. PCH Field Descriptions (continued)
Bit
0
PC16
Description
Program Counter bit 16— In Normal and Loop1 mode this bit corresponds to program counter bit 16.
8.4.5.4
Trace Buffer Organization (Compressed Pure PC mode)
Table 8-40. Trace Buffer Organization Example (Compressed PurePC mode)
Mode
Line ^2-bits
Number _{Field 3}
Line 1 00
Line 2 11
Compressed ^{Line 3 01}
Pure PC Mode _{Line 4 00}
Line 5 10
Line 6 00
6-bits
Field 2
PC4
0
0
6-bits
Field 1
PC1 (Initial 18-bit PC Base Address)
PC3
0
PC6 (New 18-bit PC Base Address)
PC8
PC9 (New 18-bit PC Base Address)
6-bits
Field 0
PC2
PC5
PC7
NOTE
Configured for end aligned triggering in compressed PurePC mode, then
after rollover it is possible that the oldest base address is overwritten. In this
case all entries between the pointer and the next base address have lost their
base address following rollover. For example in Table 8-40 if one line of
rollover has occurred, Line 1, PC1, is overwritten with a new entry. Thus the
entries on Lines 2 and 3 have lost their base address. For reconstruction of
program flow the first base address following the pointer must be used, in
the example, Line 4. The pointer points to the oldest entry, Line 2.
Field3 Bits in Compressed Pure PC Modes
Table 8-41. Compressed Pure PC Mode Field 3 Information Bit Encoding
INF1
0
0
1
1
INF0
0
1
0
1
TRACE BUFFER ROW CONTENT
Base PC address TB[17:0] contains a full PC[17:0] value
Trace Buffer[5:0] contain incremental PC relative to base address zero value
Trace Buffer[11:0] contain next 2 incremental PCs relative to base address zero value
Trace Buffer[17:0] contain next 3 incremental PCs relative to base address zero value
Each time that PC[17:6] differs from the previous base PC[17:6], then a new base address is stored. The
base address zero value is the lowest address in the 64 address range
The first line of the trace buffer always gets a base PC address, this applies also on rollover.
MC9S12G Family Reference Manual, Rev.1.23
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Freescale Semiconductor