S9S12GN32F0MLC Datasheet, PDF (415/1292 Pages) Freescale Semiconductor, Inc – MC9S12G Family Reference Manual and Data Sheet

S12 Clock, Reset and Power Management Unit (S12CPMU)
COP is written at the correct time (due to independent API interrupt request) but the wrong value is written
(alternating sequence of $55 and $AA is no longer maintained) which causes a COP reset.
MC9S12G Family Reference Manual, Rev.1.23
Freescale Semiconductor
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