P912XDP512F0MFVR datasheet(757/1350 Pages) FREESCALE

757 / 1350 page

Chapter 20 S12X Debug (S12XDBGV3) Module

MC9S12XDP512 Data Sheet, Rev. 2.17

Freescale Semiconductor

757

20.3.2.6

Debug Count Register (DBGCNT)

Read: Anytime

Write: Never

Address: 0x0026

76543210

CNT

Reset

POR

—

= Unimplemented or Reserved

Figure 20-8. Debug Count Register (DBGCNT)

Table 20-17. DBGCNT Field Descriptions

Field

Description

6–0

CNT[6:0]

Count Value — The CNT bits [6:0] indicate the number of valid data 64-bit data lines stored in the Trace Buffer.

Table 20-18 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-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.

Table 20-18. CNT Decoding Table

TBF (DBGSR)

CNT[6:0]

Description

0000000

No data valid

0000001

32 bits of one line valid1

1 This applies to Normal/Loop1 Modes when tracing from either S12XCPU or XGATE only.

0000010

0000100

0000110

1111100

1 line valid

2 lines valid

3 lines valid

62 lines valid

1111110

63 lines valid

0000000

64 lines valid; if using Begin trigger alignment,

ARM bit will be cleared and the tracing session ends.

0000010

1111110

64 lines valid,

oldest data has been overwritten by most recent data

P912XDP512F0MFVR 数据表(PDF) 757 Page - Freescale Semiconductor, Inc

P912XDP512F0MFVR 数据表(HTML) 757 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载