mc68hc908rf2 Freescale Semiconductor, Inc, mc68hc908rf2 Datasheet - Page 157

• Manufacturer Part Number: mc68hc908rf2
• Description: M68hc08 Microcontrollers Microcontroller / Transmitter
• Manufacturer: Freescale Semiconductor, Inc

Data Sheet — MC68HC908RF2
13.1 Introduction
13.2 Break Module (BRK)
13.2.1 Functional Description
MC68HC908RF2 — Rev. 4.0
MOTOROLA
This section describes the break module, the monitor module (MON), and the
monitor mode entry methods.
The break module can generate a break interrupt that stops normal program flow
at a defined address to enter a background program.
Features include:
When the internal address bus matches the value written in the break address
registers, the break module issues a breakpoint signal to the CPU. The CPU then
loads the instruction register with a software interrupt instruction (SWI) after
completion of the current CPU instruction. The program counter vectors to $FFFC
and $FFFD ($FEFC and $FEFD in monitor mode).
These events can cause a break interrupt to occur:
When a CPU-generated address matches the contents of the break address
registers, the break interrupt begins after the CPU completes its current instruction.
A return-from-interrupt instruction (RTI) in the break routine ends the break
interrupt and returns the MCU to normal operation.
structure of the break module.
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Accessible input/output (I/O) registers during break interrupts
CPU-generated break interrupts
Software-generated break interrupts
COP disabling during break interrupts
A CPU-generated address (the address in the program counter) matches
the contents of the break address registers.
Software writes a 1 to the BRKA bit in the break status and control register.
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Development Support
Section 13. Development Support
Figure 13-1
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Data Sheet
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