mc68hc908sr12 Freescale Semiconductor, Inc, mc68hc908sr12 Datasheet - Page 152

• Manufacturer Part Number: mc68hc908sr12
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

System Integration Module (SIM)
9.6 Exception Control
9.6.1 Interrupts
Data Sheet
152
INTERRUPT
INTERRUPT
MODULE
MODULE
I-BIT
I-BIT
R/W
R/W
IDB
IDB
IAB
IAB
DUMMY
DUMMY
Normal, sequential program execution can be changed in three different
ways:
At the beginning of an interrupt, the CPU saves the CPU register
contents on the stack and sets the interrupt mask (I bit) to prevent
additional interrupts. At the end of an interrupt, the RTI instruction
recovers the CPU register contents from the stack so that normal
processing can resume.
Figure 9-9
SP – 4
•
•
•
SP
Figure 9-9. Interrupt Recovery Timing
PC – 1[7:0] PC – 1[15:8]
Figure 9-8. Interrupt Entry Timing
Interrupts:
– Maskable hardware CPU interrupts
– Non-maskable software interrupt instruction (SWI)
Reset
Break interrupts
CCR
SP – 1
SP – 3
System Integration Module (SIM)
shows interrupt recovery timing.
A
SP – 2
SP – 2
X
X
Figure 9-8
SP – 3
SP – 1
PC – 1[15:8] PC – 1[7:0]
A
MC68HC908SR12•MC68HC08SR12 — Rev. 5.0
SP – 4
SP
shows interrupt entry timing, and
CCR
VECT H
PC
V DATA H
OPCODE
VECT L
PC + 1
OPERAND
V DATA L
Freescale Semiconductor
START ADDR
OPCODE