9-10
MCF5249UM
MOTOROLA
Interrupt Interface
9.4.1.2
Interrupt Pending Register
The IPR makes visible the interrupt sources that have an interrupt pending.
Table 9-14 Interrupt Mask Bit Descriptions
BIT NAME
DESCRIPTION
IMR[17:8]
Each Interrupt Mask bit corresponds to an interrupt source defined in the Interrupt Control
Register (ICR). An interrupt is masked by setting the corresponding bit in the IMR. When a
masked interrupt occurs, the corresponding bit in the IPR is still set, regardless of the setting
of the IMR bit, but no interrupt request is passed to the core processor. At system reset, all
defined bits are initialized high, thereby masking all interrupts.
The proper procedure for masking interrupt sources is to first set the core’s status register
interrupt mask level to the level of the source being masked in the IMR. Then, the IMR bit
can be masked.
An interrupt can be masked by setting the corresponding bit in the IMR and enable an
interrupt by clearing the corresponding bit in the IMR. When a masked interrupt occurs, the
corresponding bit in the IPR is still set, regardless of the setting of the IMR bit, but no
interrupt request is passed to the core processor.
RES[7:1]
Reserved.
Table 9-15 Interrupt Pending Register (IPR)
BITS
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FIELD
QSPI
DMA
3
DMA
2
RESET
—
BITS
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FIELD
DMA
1
DMA
0
UART
1
UART
0
I2C
TIMER1
TIMER0
SWT
—
RESET
—
MBAR (0X40)
Table 9-16 Interrupt Pending Bit Descriptions
BIT NAME
DESCRIPTION
IPR[18:8]
Each Interrupt Pending bit corresponds to an interrupt source defined by the Interrupt
Control Register. At every clock this register samples the signal generated by the interrupting
source. The corresponding bit in this register reflects the state of the interrupt signal even if
the corresponding mask bit were set. The IPR is a read-only longword register.
0 = The corresponding interrupt source does not have an interrupt pending
1 = The corresponding interrupt source has an interrupt pending
RES[7:1]
Reserved.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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