Cortex-R4 and Cortex-R4F Technical Reference Manual: 12.4.12. Breakpoint Value Registers

12.4.12. Breakpoint Value Registers

Each DBGBVR is associated with a Breakpoint Control Register (DBGBCR). DBGBCRy is the corresponding control register for DBGBVRy.

A pair of breakpoint registers, DBGBVRy/DBGBCRy, is called a Breakpoint Register Pair (BRP). DBGBVR0-7 are paired with DBGBCR0-7 to make BRP0-7.

The breakpoint value contained in this register corresponds to either an instruction address or a context ID. Breakpoints can be set on:

an instruction address
a context ID value
an instruction address and context ID pair.

For an instruction address and context ID pair, two BRPs must be linked. A debug event is generated when both the instruction address and the context ID pair match at the same time.

Table 12.16 shows the DBGBVR bit assignments.

Table 12.16. Breakpoint Value Registers functions

Bits	Reset value	Description
[31:0]	`0x0`	Breakpoint value

Note

Only BRPn supports context ID comparison, where n+1 is the number of breakpoint register pairs implemented in the processor.
Bits [1:0] of Registers DBGBVR0 to DBGBVR(n-1) are Do Not Modify on writes and Read-As-Zero because these registers do not support context ID comparisons.
The contents of the CP15 Context ID Register give the context ID value for a DBGBVR to match. For information on the CONTEXTIDR, see Chapter 4 System Control.

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