mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 502

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 17 Interrupt (INTV1)
The interrupt sub-block decodes the priority of all system exception requests and provides the applicable
vector for processing the exception. The INT supports I-bit maskable and X-bit maskable interrupts, a
non-maskable unimplemented opcode trap, a non-maskable software interrupt (SWI) or background
debug mode request, and three system reset vector requests. All interrupt related exception requests are
managed by the interrupt sub-block (INT).
17.1.1
The INT includes these features:
17.1.2
The functionality of the INT sub-block in various modes of operation is discussed in the subsections that
follow.
502
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Provides two to 122 I-bit maskable interrupt vectors (0xFF00–0xFFF2)
Provides one X-bit maskable interrupt vector (0xFFF4)
Provides a non-maskable software interrupt (SWI) or background debug mode request vector
(0xFFF6)
Provides a non-maskable unimplemented opcode trap (TRAP) vector (0xFFF8)
Provides three system reset vectors (0xFFFA–0xFFFE) (reset, CMR, and COP)
Determines the appropriate vector and drives it onto the address bus at the appropriate time
Signals the CPU that interrupts are pending
Provides control registers which allow testing of interrupts
Provides additional input signals which prevents requests for servicing I and X interrupts
Wakes the system from stop or wait mode when an appropriate interrupt occurs or whenever XIRQ
is active, even if XIRQ is masked
Provides asynchronous path for all I and X interrupts, (0xFF00–0xFFF4)
(Optional) selects and stores the highest priority I interrupt based on the value written into the
HPRIO register
Normal operation
The INT operates the same in all normal modes of operation.
Special operation
Interrupts may be tested in special modes through the use of the interrupt test registers.
Emulation modes
The INT operates the same in emulation modes as in normal modes.
Low power modes
See
Section 17.4.1, “Low-Power
Features
Modes of Operation
MC9S12E256 Data Sheet, Rev. 1.08
Modes,” for details
Freescale Semiconductor