mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 203

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

6.3.2.6
Read: Anytime
Write: Never
6.3.2.7
There is a dedicated control register for each of the state sequencer states 1 to 3 that determines if
transitions from that state are allowed, depending upon comparator matches or tag hits, and defines the
Freescale Semiconductor
Address: 0x0026
CNT[6:0]
Reset
Field
POR
6–0
W
R
TBF (DBGSR)
Count Value — The CNT bits [6:0] indicate the number of valid data 64-bit data lines stored in the Trace Buffer.
Table 6-17
When the CNT rolls over to zero, the TBF bit in DBGSR is set and incrementing of CNT will continue in end-
trigger or mid-trigger mode. The DBGCNT register is cleared when ARM in DBGC1 is written to a one. The
DBGCNT register is cleared by power-on-reset initialization but is not cleared by other system resets. Thus
should a reset occur during a debug session, the DBGCNT register still indicates after the reset, the number of
valid trace buffer entries stored before the reset occurred. The DBGCNT register is not decremented when
reading from the trace buffer.
Debug Count Register (DBGCNT)
Debug State Control Registers
0
0
0
7
0
0
0
0
1
1
= Unimplemented or Reserved
shows the correlation between the CNT bits and the number of valid data lines in the Trace Buffer.
—
0
6
CNT[6:0]
0000000
0000001
0000010
0000100
0000110
1111100
1111110
0000000
0000010
1111110
Figure 6-8. Debug Count Register (DBGCNT)
..
..
..
Table 6-16. DBGCNT Field Descriptions
S12XS Family Reference Manual, Rev. 1.10
Table 6-17. CNT Decoding Table
—
0
5
oldest data has been overwritten by most recent data
ARM bit will be cleared and the tracing session ends.
64 lines valid; if using Begin trigger alignment,
—
0
4
Description
32 bits of one line valid
CNT
—
64 lines valid,
No data valid
62 lines valid
63 lines valid
0
3
Description
2 lines valid
3 lines valid
1 line valid
..
—
0
2
S12X Debug (S12XDBGV3) Module
—
0
1
—
0
0
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