
Enhanced Direct Memory Access Controller (eDMA)
PXN20 Microcontroller Reference Manual, Rev. 1
24-36
Freescale Semiconductor
Figure 24-22. Example of Multiple Loop Iterations
lists the memory array terms and how the TCD settings interrelate.
Figure 24-23. Memory Array Terms
24.5.2
DMA Programming Errors
The DMA performs various tests on the transfer control descriptor to verify consistency in the descriptor
data. Most programming errors are reported on a per-channel basis with the exception of two errors:
group-priority error and channel-priority error, or EDMA_ESR[GPE] and EDMA_ESR[CPE],
respectively.
For all error types other than group- or channel-priority errors, the channel number causing the error is
recorded in the EDMA_ESR. If the error source is not removed before the next activation of the problem
channel, the error is detected and recorded again.
DMA request
Minor loop
3
Current major loop
iteration count
(CITER)
Example memory array
•
•
•
DMA request
Minor loop
2
•
•
•
DMA request
Minor loop
1
•
•
•
Major loop
xADDR:
(Starting address)
xSIZE:
(Size of one data
Minor loop
(NBYTES in
minor loop, often
the same value
as xSIZE)
Offset (xOFF): Number of
bytes added to current
address after each transfer
(Often the same value
as xSIZE)
•
Minor loop
Each DMA source (S) and
destination (D) has its own:
• Address (xADDR)
• Size (xSIZE)
• Offset (xOFF)
xLAST: Number of bytes
added to current address
Peripheral queues typically
have size and offset
equal to NBYTES
•
•
after major loop
(typically used to
loop back)
transfer)
•
•
•
•
•
•
Last minor loop
• Modulo (xMOD)
• Last address adjustment
(xLAST) where x = S or D
•
•
•
Содержание PXN2020
Страница 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Страница 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Страница 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Страница 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Страница 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Страница 162: ...Clocks Reset and Power CRP PXN20 Microcontroller Reference Manual Rev 1 6 30 Freescale Semiconductor...
Страница 182: ...Frequency Modulated Phase Locked Loop FMPLL PXN20 Microcontroller Reference Manual Rev 1 7 20 Freescale Semiconductor...
Страница 268: ...Boot Assist Module BAM PXN20 Microcontroller Reference Manual Rev 1 9 14 Freescale Semiconductor...
Страница 318: ...Interrupts and Interrupt Controller INTC PXN20 Microcontroller Reference Manual Rev 1 10 50 Freescale Semiconductor...
Страница 326: ...General Purpose Static RAM SRAM PXN20 Microcontroller Reference Manual Rev 1 11 8 Freescale Semiconductor...
Страница 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Страница 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Страница 460: ...Memory Protection Unit MPU PXN20 Microcontroller Reference Manual Rev 1 18 20 Freescale Semiconductor...
Страница 478: ...Error Correction Status Module ECSM PXN20 Microcontroller Reference Manual Rev 1 19 18 Freescale Semiconductor...
Страница 488: ...Software Watchdog Timer SWT PXN20 Microcontroller Reference Manual Rev 1 20 10 Freescale Semiconductor...
Страница 494: ...System Timer Module STM PXN20 Microcontroller Reference Manual Rev 1 21 6 Freescale Semiconductor...
Страница 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Страница 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Страница 926: ...Controller Area Network FlexCAN PXN20 Microcontroller Reference Manual Rev 1 29 42 Freescale Semiconductor...
Страница 990: ...Deserial Serial Peripheral Interface DSPI PXN20 Microcontroller Reference Manual Rev 1 30 64 Freescale Semiconductor...
Страница 1044: ...Enhanced Serial Communication Interface eSCI PXN20 Microcontroller Reference Manual Rev 1 31 54 Freescale Semiconductor...
Страница 1080: ...Cross Triggering Unit CTU PXN20 Microcontroller Reference Manual Rev 1 33 12 Freescale Semiconductor...
Страница 1134: ...Analog to Digital Converter ADC PXN20 Microcontroller Reference Manual Rev 1 34 54 Freescale Semiconductor...
Страница 1150: ...IEEE 1149 1 Test Access Port Controller JTAGC PXN20 Microcontroller Reference Manual Rev 1 35 16 Freescale Semiconductor...
Страница 1257: ...Nexus Development Interface NDI PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 36 107...
Страница 1258: ...Nexus Development Interface NDI PXN20 Microcontroller Reference Manual Rev 1 36 108 Freescale Semiconductor...
Страница 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...