![Freescale Semiconductor PXR4030 Скачать руководство пользователя страница 1084](http://html1.mh-extra.com/html/freescale-semiconductor/pxr4030/pxr4030_reference-manual_23306601084.webp)
Enhanced Queued Analog-to-Digital Converter (EQADC)
27-102
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
AD conversion accuracy can be affected by the settling time of the input channel multiplexers. Some time
is required for the channel multiplexers internal capacitances to settle after the channel number is changed.
If the time prior to sampling is not long enough to absorb this settling, then the settling time will take from
ADC sampling time which may result in inaccurate sampling and ultimately compromise conversion result
accuracy - see
(a). The EQADC attempts to compensate for this settling time by switching
the multiplexers in preparation for the next conversion command's sampling while performing the
previous conversion
(
(b)). In EQADC, this is done in the following way; when a conversion
command is in buffer ENTRY1 and another conversion command is identified in ENTRY0, then the
channel number of ENTRY0 is sent to the
MUX Control Logic
some cycles before the sampling phase of
the command in ENTRY0 starts. In this way, sampling for the next command can promptly start after the
current conversion finishes because the internal capacitance of the multiplexers will be settled by that time,
allowing for more accurate sampling. This is specially important for applications that require high
conversion speeds, that is with the ADC running at maximum clock frequency and with the analog input
voltage sampling time set to a minimum (2 ADC clock cycles), when the short sampling time does not
allow the multiplexers to completely settle. The second advantage of pipelining conversion commands is
to provide precise conversion intervals, which means the time intervals between two consecutive
conversions are the same. This is important for any digital signal process application.
When the on-chip ADC abort feature is enabled, ADC Commands from CFIFO0 should be considered
immediately, even stopping the execution of some command that is already in ENTRY1. When the abort
request is sent to the ADC, the already stored commands in the CBuffers are copied in a temporary set of
registers. The first ADC command from CFIFO0 is sent after the abort acknowledge indication from ADC.
The process is the same as usual until the transfer of the last command from CFIFO0. Then the temporarily
stored commands that were postponed by the abortion are recovered and they are pipelined for execution.
After the last command from this temporary memory is transferred, the next commands are pipelined from
the CFIFOs.
Содержание PXR4030
Страница 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Страница 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Страница 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Страница 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Страница 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 158: ...Power Management Controller PMC 5 26 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 182: ...Frequency Modulated Phase Locked Loop FMPLL 6 24 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 278: ...System Integration Unit SIU 7 96 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 280: ...System Information Module PXR40 Microcontroller Reference Manual Rev 1 8 2 Freescale Semiconductor...
Страница 300: ...Boot Assist Module BAM 9 20 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 346: ...Interrupts and Interrupt Controller INTC 10 46 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 352: ...General Purpose Static RAM SRAM 11 6 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 432: ...Core e200z7 Overview PXR40 Microcontroller Reference Manual Rev 1 13 44 Freescale Semiconductor...
Страница 460: ...Peripheral Bridge PBRIDGE 15 16 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 478: ...Memory Protection Unit MPU 16 18 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 496: ...Error Correction Status Module ECSM 17 18 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 524: ...Periodic Interrupt Timer PIT_RTI 20 12 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 740: ...FlexRay Communication Controller FLEXRAY 22 156 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 928: ...Deserial Serial Peripheral Interface DSPI 25 68 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 982: ...Enhanced Serial Communication Interface eSCI 26 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 1114: ...Enhanced Queued Analog to Digital Converter EQADC 27 132 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
Страница 1168: ...Decimation Filter 28 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 1262: ...Enhanced Time Processing Unit eTPU2 29 94 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Страница 1399: ...Nexus Development Interface NDI Freescale Semiconductor 31 83 PXR40 Microcontroller Reference Manual Rev 1...
Страница 1400: ...Nexus Development Interface NDI 31 84 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...