MC68HC908GP32_08 Datasheet, PDF (88/266 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Computer Operating Properly (COP)
To prevent inadvertently turning off the COP with a STOP instruction, a configuration option is available
that disables the STOP instruction. When the STOP bit in the configuration register has the STOP
instruction is disabled, execution of a STOP instruction results in an illegal opcode reset.
7.8 COP Module During Break Mode
The COP is disabled during a break interrupt when V_TST is present on the RST pin.
MC68HC908GP32 Data Sheet, Rev. 10
88
Freescale Semiconductor