Direct Memory Access (DMA)
C2000 Microcontroller Workshop - Direct Memory Access Controller
9 - 9
Priority Modes and the State Machine
Read/Write Data
Add Burst Step
to Address
Pointer
Add Transfer
Step to Address
Pointer
Moved
“Burst Size”
Words?
Moved
“Transfer Size”
Bursts?
Y
Y
N
N
Point where other
pending channels
are serviced
Wait for event
to start/continue
transfer
Point where
CH1 can
interrupt other
channels in
CH1 Priority Mode
Start Transfer
End Transfer
DMA Throughput
DMA Throughput
4 cycles/word
(5 for McBSP reads)
1 cycle delay to start each burst
1 cycle delay returning from CH1
high priority interrupt
32-bit transfer doubles throughput
(except McBSP, which supports 16-bit transfers only)
Example: 128 16-bit words from ADC to RAM
8 bursts * [(4 cycles/word * 16 words/burst) + 1] =
520 cycles
Example: 64 32-bit words from ADC to RAM
8 bursts * [(4 cycles/word * 8 words/burst) + 1] =
264 cycles
Содержание C2000 Piccolo LaunchPad
Страница 74: ...Interrupts 4 18 C2000 Microcontroller Workshop Reset and Interrupts ...
Страница 100: ...Lab 5 System Initialization 5 26 C2000 Microcontroller Workshop System Initialization ...
Страница 126: ...Lab 6 Analog to Digital Converter 6 26 C2000 Microcontroller Workshop Analog to Digital Converter ...
Страница 218: ...Lab 8 IQmath FIR Filter 8 42 C2000 Microcontroller Workshop Numerical Concepts ...
Страница 236: ...Lab 9 Servicing the ADC with DMA 9 18 C2000 Microcontroller Workshop Direct Memory Access Controller ...
Страница 260: ...Lab 10 CLA Floating Point FIR Filter 10 24 C2000 Microcontroller Workshop Control Law Accelerator ...
Страница 331: ...C2000 Microcontroller Workshop Appendix A Experimenter s Kit A 1 Appendix A Experimenter s Kit ...
Страница 334: ...F28069 controlCARD A 4 C2000 Microcontroller Workshop Appendix A Experimenter s Kit SW2 ...
Страница 336: ...F28035 controlCARD A 6 C2000 Microcontroller Workshop Appendix A Experimenter s Kit SW2 SW3 ...
Страница 338: ...F28335 controlCARD A 8 C2000 Microcontroller Workshop Appendix A Experimenter s Kit LD1 LD2 LD3 SW1 ...