B.7.6. Debug request

Entry into debug state through a debug request is similar to a breakpoint. Entry to debug from ARM or Thumb state adds four addresses to the PC, and every instruction executed in debug state adds one address, and from Jazelle state adds four bytes.

For example, the following sequence handles a situation in which the user has invoked a debug request when in ARM or Thumb state, and then decides to return to program execution immediately:

0 EAFFFFFB; B minus five addresses (2’s complement)

1 E1A00000; NOP (MOV R0, R0), SYSSPEED bit is set

This code restores the PC, and restarts the program from the next instruction.

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