9
9-16
Ver.0.10
DMAC
9.2 DMAC Related Registers
The DMA Channel Control Register consists of bits to select DMA transfer mode in each channel,
set DMA transfer request flag, and the bits to select the cause of DMA request, enable DMA
transfer, and set the transfer size and the source/destination address directions.
(1) MDSELn (DMAn transfer mode select) bit (D0)
This bit when in single transfer mode selects normal mode or ring buffer mode. Normal mode is
selected by setting this bit to 0 or ring buffer mode is selected by setting it to 1.
In ring buffer mode, transfer begins from the transfer start address and after performing transfers
32 times, control is recycled back to the transfer start address, from which transfer operation is
repeated. In this case, the Transfer Count Register counts in free-run mode during which time
transfer operation is continued until the transfer enable bit is reset to 0 (to disable transfer). No
interrupt is generated at completion of DMA transfer.
(2) TREQFn (DMAn transfer request flag) bit (D1)
This flag is set to 1 when a DMA transfer request occurs. Reading this flag helps to know DMA
transfer requests in each channel.
The generated DMA request is cleared by writing a 0 to this bit. If you write a 1, the value you
wrote is ignored and the bit retains its previous value. If a new DMA transfer request is generated
for a channel whose DMA transfer request flag has already been set to 1, the next DMA transfer
request is not accepted until the transfer under way in that channel is completed.
(3) REQSLn (cause of DMAn request select) bits (D2, D3)
These bits select the cause of DMA request in each DMA channel.
(4) TENLn (DMAn transfer enable) bit (D4)
Transfer is enabled by setting this bit to 1, so that the channel is ready for DMA transfer.
Conversely, transfer is disabled by setting this bit to 0. However, if a transfer request has already
been accepted, transfer in that channel is not disabled until after the requested transfer is
completed.
(5) TSZSLn (DMAn transfer size select) bit (D5)
This bit selects the number of bits to be transferred in one DMA transfer operation (unit of one
transfer). The unit of one transfer is 16 bits when TSZSL = 0 or 8 bits when TSZSL = 1.
(6) SADSLn (DMAn source address direction select) bit (D6)
This bit selects the direction in which the source address changes as transfer proceeds. This
mode can be selected from two choices: address fixed or address incremental.
(7) DADSLn (DAMn destination address direction select) bit (D7)
This bit selects the direction in which the destination address changes as transfer proceeds. This
mode can be selected from two choices: address fixed or address incremental.
Содержание M32170F3VFP
Страница 19: ...CHAPTER 1 CHAPTER 1 OVERVIEW 1 1 Outline of the 32170 1 2 Block Diagram 1 3 Pin Function 1 4 Pin Layout ...
Страница 42: ...1 1 24 Ver 0 10 OVERVIEW 1 4 Pin Layout This is a blank page ...
Страница 56: ...2 2 14 Ver 0 10 This is a blank page ...
Страница 88: ...3 3 32 Ver 0 10 ADDRESS SPACE 3 7 Notes on Address Space This is a blank page ...
Страница 192: ...6 6 58 Ver 0 10 INTERNAL MEMORY 6 9 Precautions to Be Taken When Rewriting Flash Memory This is a blank page ...
Страница 270: ...9 9 40 Ver 0 10 DMAC 9 4 Precautions about the DMAC This is a blank page ...
Страница 498: ...10 10 228 Ver 0 10 MULTIJUNCTION TIMERS 10 9 TOM Output related 16 bit Timer This is a blank page ...
Страница 550: ...11 11 52 Ver 0 10 A D CONVERTERS 11 4 Precautions on Using A D Converters This is a blank page ...
Страница 614: ...12 12 64 Ver 0 10 This is a blank page SERIAL I O 12 9 Precautions on Using UART Mode ...
Страница 710: ...14 14 16 Ver 0 10 REAL TIME DEBUGGER RTD 14 4 Typical Connection with the Host This is a blank page ...
Страница 746: ...16 16 20 Ver 0 10 WAIT CONTROLLER 16 3 Typical Operation of the Wait Controller This is a blank page ...
Страница 756: ...17 17 10 Ver 0 10 RAM BACKUP MODE 17 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Страница 757: ...CHAPTER 18 CHAPTER 18 OSCILLATION CIRCUIT 18 1 Oscillator Circuit 18 2 Clock Generator Circuit ...
Страница 762: ...18 18 6 Ver 0 10 OSCILLATION CIRCUIT 18 2 Clock Generator Circuit This is a blank page ...
Страница 798: ...19 19 36 Ver 0 10 JTAG 19 6 Precautions about Board Design when Connecting JTAG This is a blank page ...
Страница 830: ...21 21 24 Ver 0 10 PRELIMINARY PRELIMINARY This is a blank page ELECTRICAL CHARACTERISTICS 21 5 AC Characteristics ...
Страница 831: ...CHAPTER 22 CHAPTER 22 TYPICAL CHARACTERISTICS 22 1 A D Conversion Characteristics ...
Страница 833: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Страница 837: ...Appendix 2 1 32170 Instruction Processing Time APPENDIX 2 APPENDIX 2 INSTRUCTION PROCESSING TIME ...
Страница 841: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...