Cortex-A8 R2P2.pdf - ARM Information Center

DebugTable 12-23 Breakpoint Control Registers bit functions (continued)Bits Field Function[19:16] Linked BRP Linked BRP number. The value of this field indicates another BRP to link this one with.Note• if a BRP is linked with itself, it is Unpredictable whether a breakpoint debug event isgenerated• if this BRP is linked to another BRP that is not configured for linked context IDmatching, it is Unpredictable whether a breakpoint debug event is generated.[15:14] Secure stateaccess controlSecure state access control. This field enables the breakpoint to be conditional on thesecurity state of the processor.b00 = breakpoint matches in both Secure and Nonsecure stateb01 = breakpoint only matches in Nonsecure stateb10 = breakpoint only matches in Secure stateb11 = reserved.[13:9] - Reserved. RAZ, SBZP.[8:5] Byte addressselectByte address select. For breakpoints programmed to match an IVA, you must write aword-aligned address to the BVR. You can then use this field to program the breakpoint soit hits only if you access certain byte addresses.If you program the BRP for IVA match:b0000 = the breakpoint never hitsb0011 = the breakpoint hits if any of the two bytes starting at address BVR & 0xFFFFFFFC +0is accessedb1100 = the breakpoint hits if any of the two bytes starting at address BVR & 0xFFFFFFFC +2is accessedb1111 = the breakpoint hits if any of the four bytes starting at address BVR & 0xFFFFFFFC +0is accessed.If you program the BRP for IVA mismatch, the breakpoint hits where the corresponding IVAbreakpoint does not hit, that is, the range of addresses covered by an IVA mismatchbreakpoint is the negative image of the corresponding IVA breakpoint.If you program the BRP for context ID comparison, this field must be set to b1111.Otherwise, breakpoint and watchpoint debug events might not be generated as expected.NoteWriting a value to BCR[8:5] where BCR[8] is not equal to BCR[7], or BCR[6] is not equalto BCR[5], has Unpredictable results.12-40 Copyright © 2006-2008 ARM Limited. All rights reserved. ARM DDI 0344E