MC68HC908RK2 Datasheet, PDF (28/158 Pages) Motorola, Inc – Microcontroller Unit

Memory
Table 2-1 is a list of vector locations.
Table 2-1. Vector Locations
Address
$FFF2
$FFF3
$FFF4
$FFF5
$FFF6
$FFF7
$FFF8
$FFF9
$FFFA
$FFFB
$FFFC
$FFFD
$FFFE
$FFFF
Vector
ICG vector (high)
ICG vector (low)
TIM overflow vector (high)
TIM overflow vector (low)
TIM channel 1 vector (high)
TIM channel 1 vector (low)
TIM channel 0 vector (high)
TIM channel 0 vector (low)
IRQ/keyboard vector (high)
IRQ/keyboard vector (low)
SWI vector (high)
SWI vector (low)
Reset vector (high)
Reset vector (low)
2.3 Monitor ROM
The 768 bytes at addresses $F000–F2EF and $FEF0–$FEFF are utilized by the monitor ROM.
The address range $F000–F2EF is reserved for the monitor code functions, FLASH memory
programming, and erase algorithms.
The address range $FEF0–$FEFF holds reserved ROM addresses that contain the monitor code reset
vectors.
2.4 Random-Access Memory (RAM)
Addresses $0080–$00FF are RAM locations. The location of the stack RAM is programmable.
NOTE
For correct operation, the stack pointer must point only to RAM locations.
Before processing an interrupt, the CPU uses five bytes of the stack to save the contents of the CPU
registers.
NOTE
For M68HC05, M6805, and M146805 compatibility, the H register is not
stacked.
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 could overwrite data
in the RAM during a subroutine or during the interrupt stacking operation.
MC68HC908RK2 Data Sheet, Rev. 5.1
28
Freescale Semiconductor