Motorola ColdFire MCF5281 User Manual
Page 202
Interrupt Controller Modules
10-12
Freescale Semiconductor
10.3.6
Interrupt Control Register (ICRnx, (x = 1, 2,..., 63))
Each ICRnx specifies the interrupt level (1-7) and the priority within the level (0-7). All ICRnx registers
can be read, but only ICRn8 to ICRn63 can be written. It is the responsibility of the software to program
the ICRnx registers with unique and non-overlapping level and priority definitions. Failure to program the
ICRnx registers in this manner can result in undefined behavior. If a specific interrupt request is completely
unused, the ICRnx value can remain in its reset (and disabled) state.
6–4
LEVEL
Interrupt level. Represents the interrupt level currently being acknowledged.
3–0
PRI
Interrupt Priority. Represents the priority within the interrupt level of the interrupt currently being
acknowledged.
0 Priority 0
1 Priority 1
2 Priority 2
3 Priority 3
4 Priority 4
5 Priority 5
6 Priority 6
7 Priority 7
8 Mid-Point Priority associated with the fixed level interrupts only
7
6
5
3
2
0
Field
—
IL
IP
Reset
0000_0000
R/W
R/W (Read only for ICRn1-ICRn7)
Address
See
and
for register offsets
Note: It is the responsibility of the software to program the ICRnx registers
with unique and non-overlapping level and priority definitions. Failure to
program the ICRnx registers in this manner can result in undefined behavior.
If a specific interrupt request is completely unused, the ICRnx value can
remain in its reset (and disabled) state.
Figure 10-9. Interrupt Control Register (ICRnx)
Table 10-12. ICRnx Field Descriptions
Bits
Name
Description
7–6
—
Reserved, should be cleared.
5–3
IL
Interrupt level. Indicates the interrupt level assigned to each interrupt input.
2–0
IP
Interrupt priority. Indicates the interrupt priority for internal modules within the interrupt-level
assignment. 000b represents the lowest priority and 111b represents the highest. For the fixed level
interrupt sources, the priority is fixed at the midpoint for the level, and the IP field will always read as
000b.
Table 10-11. IACKLPRn Field Descriptions (continued)
Bits
Name
Description
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3