Program counter breakpoint and mask registers (pbr – Freescale Semiconductor MCF5480 User Manual

Page 270

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MCF548x Reference Manual, Rev. 3

8-20

Freescale Semiconductor

8.4.7

Program Counter Breakpoint and Mask Registers (PBRn, PBMR)

Each PC breakpoint register (PBR, PBR1, PBR2, PBR3) defines an instruction address for use as part of

the trigger. These registers’ contents are compared with the processor’s program counter register when the

appropriate valid bit is set, and TDR or XTDR are configured appropriately. PBR bits are masked by

setting corresponding PBMR bits. Results are compared with the processor’s program counter register, as

defined in TDR or XTDR. PBR1–PBR3 are not masked.

Figure 8-11

shows the PC breakpoint register.

PC breakpoint registers are accessible in supervisor mode using the WDEBUG instruction and through the

BDM port using the

RDMREG

and

WDMREG

commands using values shown in

Section 8.5.3.3, “Command

Set Descriptions

.”

Table 8-13

describes PBR, PBR1, PBR2, and PBR3 fields.

2

EAL1

Address enable bit: Enable address breakpoint low. The breakpoint is based on the address in the
ABLR. Trigger address = ABLR

1

EPC1

Enable PC breakpoint. If set, this bit enables the PC breakpoint for the first level trigger.

0

PCI1

Breakpoint invert. If set, this bit allows execution outside a given region as defined by
PBR/PBR1/PBR2/PBR3 and PBMR to enable a trigger. If cleared, the PC breakpoint is defined
within the region defined by PBR/PBR1/PBR2/PBR3 and PBMR.

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

R

CNTRAD

W

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

R

CNTRAD

0

W

V

1

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Reg

Addr

CPU + 0x08 (PBR); 0x18 (PBR1); 0x1A (PBR2); 0x1B (PBR3)

1

PBR0 does not have a valid bit. PBR0 is read as 0 and should be cleared.

Figure 8-11. Program Counter Breakpoint Registers (PBR, PBR1, PBR2, PBR3)

Table 8-12. TDR Field Descriptions (Continued)

Bits

Name

Description

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