System Integration Unit (SIU)
7-22
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
7.3.1.11
IRQ Digital Filter Register (SIU_IDFR)
The SIU_IDFR specifies the amount of digital filtering on IRQ[0]–IRQ[15]. The digital filter length field
specifies the number of system clocks that define the period of the digital filter and the minimum time an
IRQ signal must hold the active state to qualify as an edge-triggered event.
The following table describes the field in the IRQ digital filter register:
7.3.1.12
IRQ Filtered Input Register (SIU_IFIR)
The SIU_IFIR is a read only register where the filtered values of the NMI and IRQ[0]–IRQ[15] pins are
captured.
Address: SI 0x0030
Access: R/W
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
R
0
0
0
0
0
0
0
0
0
0
0
0
DFL
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 7-12. IRQ Digital Filter Register (SIU_IDFR)
Table 7-18. SIU_IDFR Bit Field Descriptions
Field
Function
0–27
Reserved
28–31
DFL
Digital filter length. Defines the digital filter period on the IRQ[n] inputs according to the following equation:
For a 100 MHz system clock, this gives a range of 20 ns to 328
µ
s. The minimum time of three clocks accounts for
synchronization of the IRQ input pins with the system clock.
Filter Period
SystemClockPeriod
2
DFL
1 S
ystemClockPeriod
+
=
Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Page 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
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Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
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