UM0434 datasheet(68/390 Pages) STMICROELECTRONICS

68 / 390 page

UM0434

69/391

4.11.5

Decrementer auto-reload register (DECAR)

If the auto-reload function is enabled (TCR[ARE] = 1), the auto-reload value in DECAR,

shown in

Table 46, is written to DEC when DEC decrements from 0x0000_0001 to

0x0000_0000. Writing DEC with zeros by using an mtspr does not automatically generate a

decrementer interrupt.

4.12

Debug registers

This section describes software-accessible debug registers for use by special debug tools

and debug software, not by general application code. Software access to these registers is

conditioned by the external debug mode control bit (DBCR0[EDM]), which can be set by the

hardware debug port. If DBCR0[EDM] is set, software is prevented from modifying debug

modifications to occur. In addition, since the external debugger hardware may be

manipulating debug register values, the state of these registers is not guaranteed to be

consistent if read by software with an mfspr instruction other than DBCR0[EDM].

4.12.1

Debug address and value registers

Instruction address compare registers IAC1–IAC4 hold instruction addresses for

comparison. In addition, IAC2 and IAC4 hold mask information for IAC1 and IAC3,

respectively, when address bit match compare modes are selected.

Note:

During instruction address comparisons, the low-order two address bits of the instruction

address and the corresponding IAC register are ignored.

Data address compare registers DAC1 and DAC2 hold data access addresses for

comparison. In addition, DAC2 holds mask information for DAC1 when address bit match

compare mode is selected.

Instruction address compare registers (IAC1–IAC4)

IAC1–IAC4, shown in

Table 47, hold instruction addresses for comparison.

Table 46.

Decrementer auto-reload register (DECAR)

Field

Decrementer auto-reload value

Reset

Undefined on

m_por assertion, unchanged on p_reset_b assertion

R/W

SPR

SPR 54

Table 47.

Instruction address compare registers (IAC1–IAC4)

616263

Field

Instruction address

—

Reset

All zeros

R/W

SPR

SPR 312 (IAC1); SPR 313 (IAC2); SPR 314 (IAC3); SPR 315 (IAC4)

UM0434 Datasheet(PDF) 68 Page - STMicroelectronics

UM0434 Datasheet(HTML) 68 Page - STMicroelectronics

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

Datasheet Download

Link URL