S912XEG128J2VAL
| Model | S912XEG128J2VAL |
| Description | IC,MICROCONTROLLER,16-BIT,CPU12 CPU,CMOS,QFP,112PIN,PLASTIC |
| PDF file | Total 1327 pages (File size: 7M) |
| Chip Manufacturer | ROCHESTER |
Chapter 8 S12X Debug (S12XDBGV3) Module
8.3.2.6
Debug Count Register (DBGCNT)
Because of an order from the United States International Trade Commission, BGA-packaged product lines and part numbers indicated here currently are not
available from Freescale for import or sale in the United States prior to September 2010: S12XE products in 208 MAPBGA packages
Address: 0x0026
7
6
5
4
3
2
1
0
R
W
Reset
POR
0
0
0
—
0
—
0
—
0
CNT
—
0
—
0
—
0
—
0
= Unimplemented or Reserved
Figure 8-8. Debug Count Register (DBGCNT)
Read: Anytime
Write: Never
Table 8-19. DBGCNT Field Descriptions
Field
6–0
CNT[6:0]
Description
Count Value
— The CNT bits [6:0] indicate the number of valid data 64-bit data lines stored in the Trace Buffer.
Table 8-20
shows the correlation between the CNT bits and the number of valid data lines in the Trace Buffer.
When the CNT rolls over to zero, the TBF bit in DBGSR is set and incrementing of CNT will continue in end-
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.
Table 8-20. CNT Decoding Table
TBF (DBGSR)
0
0
0
CNT[6:0]
0000000
0000001
0000010
0000100
0000110
..
1111100
1111110
0000000
Description
No data valid
32 bits of one line valid
(1)
1 line valid
2 lines valid
3 lines valid
..
62 lines valid
63 lines valid
64 lines valid; if using Begin trigger alignment,
ARM bit will be cleared and the tracing session ends.
0
1
1
64 lines valid,
0000010
oldest data has been overwritten by most recent data
..
..
1111110
1. This applies to Normal/Loop1/PurePC Modes when tracing from either CPU12X or XGATE only.
MC9S12XE-Family Reference Manual , Rev. 1.19
314
Freescale Semiconductor
