Section 6 User Break Controller (UBC)
6.1
Overview
The user break controller (UBC) simplifies the debugging of user programs. Break conditions are
set in the UBC and a user break interrupt request is sent to the CPU in response to the contents of
a CPU or DMAC bus cycle. This function can implement an effective self-monitoring debugger,
enabling a program to be debugged by itself without using a large in-circuit emulator.
6.1.1
Features
• The following break conditions can be set:
Address
CPU cycle or DMA cycle
Instruction fetch or data access
Read or write
Operand size (longword access, word access, or byte access)
• When break conditions are met, a user break interrupt is generated. A user-created user break
interrupt exception routine can then be executed.
• When a break is set to a CPU instruction fetch, the break occurs just before the fetched
instruction.
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