mc68hc05j5ap Freescale Semiconductor, Inc, mc68hc05j5ap Datasheet - Page 27

• Manufacturer Part Number: mc68hc05j5ap
• Description: General Description The Mc68hc05j5a Is A Member Of The Low-cost High-performance M68hc05 Family Of 8-bit Microcontroller Units Mcus . The M68hc05 Family Is Based On The Customer-speci Ed Integrated Circuit Design Strategy. All Mcus In The Family
• Manufacturer: Freescale Semiconductor, Inc

4.1
REV 2.1
The MCU can be interrupted in six different ways:
CPU INTERRUPT PROCESSING
Interrupts cause the processor to save register contents on the stack and to set
the interrupt mask (I-bit) to prevent additional interrupts. Unlike RESET, hardware
interrupts do not cause the current instruction execution to be halted, but are con-
sidered pending until the current instruction is complete.
If interrupts are not masked (I-bit in the CCR is clear) and the corresponding inter-
rupt enable bit is set the processor will proceed with interrupt processing. Other-
wise, the next instruction is fetched and executed. If an interrupt occurs the
processor completes the current instruction, then stacks the current CPU register
states, sets the I-bit to inhibit further interrupts, and finally checks the pending
hardware interrupts. If more than one interrupt is pending following the stacking
operation, the interrupt with the highest vector location shown in Table 4-1 will be
serviced first. The SWI is executed the same as any other instruction, regardless
of the I-bit state.
When an interrupt is to be processed the CPU fetches the address of the appro-
priate interrupt software service routine from the vector table at locations $0FF6
thru $0FFF as defined in Table 4-1.
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Register
TCSR
TCSR
T1SR
ICSR
N/A
N/A
Non-maskable Software Interrupt Instruction (SWI)
External Asynchronous Interrupt (IRQ)
Optional External Interrupt via IRQ on PA0-PA3 (by a mask option)
External Interrupt via IRQ on PA7
Multi-Function Timer (MFT)
16-Bit Timer Interrupt (Timer1)
Table 4-1. Vector Address for Interrupts and Reset
IRQF/IRQF1
T1OF, ICF
Name
RTIF
TOF
Flag
Freescale Semiconductor, Inc.
N/A
N/A
For More Information On This Product,
Reset
Software
External Interrupt
MFT Overflow
Real Time Interrupt
Timer1 Interrupt
Go to: www.freescale.com
INTERRUPTS
Interrupts
SECTION 4
INTERRUPTS
July 16, 1999
Interrupt
TIMER1
RESET
CPU
MFT
MFT
SWI
IRQ
GENERAL RELEASE SPECIFICATION
Vector Address
$0FFC-$0FFD
$0FFE-$0FFF
$0FFA-$0FFB
$0FF8-$0FF9
$0FF8-$0FF9
$0FF6-$0FF7
4-1