mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 334

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

Introduction
The basic ColdFire interrupt controller supports up to 63 request sources mapped as nine
priorities for each of the seven supported levels (7 levels × 9 priorities per level). Within
the nine priorities within a level, the mid-point is typically reserved for package-level
IRQ inputs. The levels and priorities within the level follow a descending order: 7 > 6
> ... > 1 > 0.
The HCS08 architecture supports a 32-entry exception vector table: the first two vectors
are reserved for internal CPU/system exceptions and the remaining are available for I/O
interrupt requests. The requirement for an exact match between the interrupt requests and
priorities across two architectures means the sources are mapped to a sparsely-populated
two-dimensional ColdFire array of seven interrupt levels and nine priorities within the
level. The following association between the HCS08 and ColdFire vector numbers
applies:
ColdFire Vector Number = 62 + HCS08 Vector Number
The CF1_INTC performs a cycle-by-cycle evaluation of the active requests and signals
the highest-level, highest-priority request to the V1 ColdFire core in the form of an
encoded interrupt level and the exception vector associated with the request. The module
also includes a byte-wide interface to access its programming model. These interfaces are
shown in the following simplified block diagram.
MCF51JF128 Reference Manual, Rev. 2, 03/2011
Preliminary
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