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Enhanced Queued Analog-to-Digital Converter (EQADC)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
1085
25.6.2.3.2
Message Formats for External Device Operation
This section describes the Command Messages, Data Messages, and Null Messages formats used for
external device operation.
Command Message Format for External Device Operation
describes the command message format for external device operation. Command message
formats for on-chip operation and for external device operation share the same CFIFO header format.
However, there are no limitations regarding the format an ADC Command used to communicate to an
arbitrary external device. Only the upper bit of an ADC Command has a fixed format (BN field) to indicate
to the
FIFO Control Unit
/external device to which CBuffer the corresponding command should be sent.
The remaining 25 bits can be anything decodable by the external device. Only the ADC Command portion
of a command message is transferred to the external device.
Differential
Conversion
s
2.56
-
-
0xFFF
0x3FFC
0x1FFC
-
0x3FF
-
0x3FF0
0x1FF0
0xFF
-
-
0x3FC0
0x1FC0
2.56 - LSB
-
-
0xFFF
0x3FFC
0x1FFC
-
0x3FF
-
0x3FF0
0x1FF0
0xFF
-
-
0x3FC0
0x1FC0
...
...
...
...
...
...
0
-
-
0x800
0x2000
0x0000
-
0x200
-
0x2000
0x0000
0x80
-
-
0x2000
0x0000
...
...
...
...
...
...
2.56 - LSB
-
-
0x001
0x0004
0xE004
-
0x001
-
0x0010
0xE010
0x01
-
-
0x0040
0xE040
-2.56
0x00
0x000
0x000
0x0000
0xE000
1
VREF=VRH-VRL=5.12V. Resulting in one 12-bit count (LSB) =1.25mV.
2
The two’s complement representation is used to express negative values.
3
Assuming uncalibrated conversion results.
Table 25-58. Correspondence between analog voltages and digital values
1, 2
Voltage Level
on Channel
(V)
Corresponding
8-bit
Conversion
Result
Returned by
the ADC
Corresponding
10-bit
Conversion
Result
Returned by
the ADC
Corresponding
12-bit
Conversion
Result
Returned by
the ADC
16-bit Result
Sent to
RFIFOs
(FMT=0)
3
16-bit Result
Sent to
RFIFOs
(FMT=1)
3
Summary of Contents for MPC5644A
Page 2: ...MPC5644A Microcontroller Reference Manual Rev 6 2 Freescale Semiconductor...
Page 24: ...MPC5644A Microcontroller Reference Manual Rev 6 24 Freescale Semiconductor...
Page 26: ...MPC5644A Microcontroller Reference Manual Rev 6 26 Freescale Semiconductor...
Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Page 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...