7.3.4.9 Setting Software Breakpoints
Software breakpoints may be set by replacing the instruction with a
TRAP
instruction (opcode 0xA5
). Upon execution of
the TRAP
instruction, the core switches to Debug mode and asserts
DebugAck. Through the JTAG port, the debugger system periodically polls Status.DebugAck
(by issuing the DebugNOP
JTAG instruction) and begins breakpoint
processing when it becomes asserted. For breakpoints in read-only memories, Debug
triggers may be used to set hardware breakpoints.