NXP Semiconductors MC9S12G User Manual

S12S Debug Module (S12SDBGV2)
MC9S12G Family Reference Manual Rev.1.27
336 NXP Semiconductors
8.4.5.4 Trace Buffer Organization (Compressed Pure PC mode)
Table 8-40. Trace Buffer Organization Example (Compressed PurePC mode)
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
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.
0
PC16
Program Counter bit 16— In Normal and Loop1 mode this bit corresponds to program counter bit 16.
Mode
Line
Number
2-bits 6-bits 6-bits 6-bits
Field 3 Field 2 Field 1 Field 0
Compressed
Pure PC Mode
Line 1 00 PC1 (Initial 18-bit PC Base Address)
Line 2 11 PC4 PC3 PC2
Line 3 01 0 0 PC5
Line 4 00 PC6 (New 18-bit PC Base Address)
Line 5 10 0 PC8 PC7
Line 6 00 PC9 (New 18-bit PC Base Address)
Table 8-41. Compressed Pure PC Mode Field 3 Information Bit Encoding
INF1 INF0 TRACE BUFFER ROW CONTENT
0 0 Base PC address TB[17:0] contains a full PC[17:0] value
0 1 Trace Buffer[5:0] contain incremental PC relative to base address zero value
1 0 Trace Buffer[11:0] contain next 2 incremental PCs relative to base address zero value
1 1 Trace Buffer[17:0] contain next 3 incremental PCs relative to base address zero value
Table 8-39. PCH Field Descriptions (continued)
Bit Description

NXP Semiconductors MC9S12G Specifications

General

Brand	NXP Semiconductors
Model	MC9S12G
Category	Microcontrollers
Language	English