Decimation Filter
28-50
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
28.5.2.1.3
eQADC Configuration for Decimation Filter
Configure an Alternate Configuration Control Register (ADC_ACR1 to ADC_ACR8) to select
Decimation Filter A as the destination for an ADC conversion, by setting ADC_ACRn[DEST] = 1. To
select a signed format, ADC_ACRn[FMTA]=1.
The ADC_ACRn register format has the form:
Note that the ADC_ADRn registers are internal to the ADC and can only be accessed indirectly by writing
a register write command to the
eQADC
CFIFO. To do this the CPU should write a command to any
eQADC
CFIFO with the following format:
For example, to update ADC_ACR1[DEST] = 1, ADC_ACR1[FMTA]=1
•
set the bit field ADC_REG_ADDRESS = 0x30
•
set the bit field ADC_REGISTER LOW BYTE = 0x00
•
set the bit field ADC_REGISTER HIGH BYTE = 0x06
28.5.2.1.4
eQADC Command
To cause the ADC conversion to be transferred to the Decimation filter selected by the method described
in Section 28.5.2.1.3, a Conversion Command for Alternate Configurations must be applied to the
eQADC
CFIFO. The form of the command is as follows:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
RET_
INH
0
DEST
FMTA
0
RESSEL
0
0
ATBSEL
PRE_GAIN
W
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
EOQ PAUSE REP
RESERVED
EB
(0b0)
BN
R/W
(0b0)
ADC_REGISTER HIGH BYTE
CFIFO Header
ADC Command
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
ADC_REGISTER LOW BYTE
ADC_REG_ADDRESS
ADC Command
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
EOQ PAUSE REP
RESERVED
EB
(0b0)
BN
CAL
MESSAGE_TAG
LST
TSR
FFMT
CFIFO Header
ADC Command
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
CHANNEL_NUMBER
ALT_CONFIG_SEL
ADC Command
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...
Page 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
Page 1168: ...Decimation Filter 28 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...