mc68hc908jb8 Freescale Semiconductor, Inc, mc68hc908jb8 Datasheet - Page 246

• Manufacturer Part Number: mc68hc908jb8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Break Module (BREAK)
17.3 Features
17.4 Functional Description
Technical Data
246
Features of the break module include the following:
When the internal address bus matches the value written in the break
address registers, the break module issues a breakpoint signal (BKPT)
to the SIM. The SIM then causes the CPU to load 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.
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Accessible i/o registers during the break interrupt
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 logic 1 to the BRKA bit in the break status and
control register.
Figure 17-1
Break Module (BREAK)
MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3
shows the structure of the break module.
Freescale Semiconductor