MC68HC708MP16 Datasheet, PDF (95/398 Pages) Freescale Semiconductor, Inc – Microcontrollers

System Integration Module (SIM)
CLI
LDA #$FF
INT1
PSHH
PULH
RTI
BACKGROUND ROUTINE
INT1 INTERRUPT SERVICE ROUTINE
INT2
PSHH
PULH
RTI
INT2 INTERRUPT SERVICE ROUTINE
Figure 7-11. Interrupt Recognition Example
The LDA opcode is prefetched by both the INT1 and INT2 RTI
instructions. However, in the case of the INT1 RTI prefetch, this is a
redundant operation.
NOTE:
To maintain compatibility with the M6805 Family, the H register is not
pushed on the stack during interrupt entry. If the interrupt service routine
modifies the H register or uses the indexed addressing mode, software
should save the H register and then restore it prior to exiting the routine.
7.6.1.2 SWI Instruction
The SWI instruction is a non-maskable instruction that causes an
interrupt regardless of the state of the interrupt mask (I bit) in the
condition code register.
NOTE: A software interrupt pushes PC onto the stack. A software interrupt does
not push PC – 1, as a hardware interrupt does.
MC68HC708MP16 — Rev. 3.1
Freescale Semiconductor
System Integration Module (SIM)
Technical Data
95