Datasheet

Random-Access Memory (RAM)
Technical Data MC68HC908LJ12 — Rev. 2.1
60 Random-Access Memory (RAM) Freescale Semiconductor
During a subroutine call, the CPU uses two bytes of the stack to store
the return address. The stack pointer decrements during pushes and
increments during pulls.
NOTE: Be careful when using nested subroutines. The CPU may overwrite data
in the RAM during a subroutine or during the interrupt stacking
operation.