9
9-17
Rev.1.0
The DMA Channel Control Register consists of a bit to select DMA transfer mode for each channel,
set DMA transfer request flag, and the bits to select the cause of DMA request, enable a DMA
transfer, set the transfer size, and source/destination address directions.
(1) MDSELn (DMAn transfer mode select) bit (D0)
This bit when in single transfer mode selects normal or ring buffer mode. Setting this bit to 0
selects normal mode, and setting this bit to 1 selects ring buffer mode.
In ring buffer mode, operation starts from the transfer start address and when transferred 32
times, returns to the transfer start address again, from which transfer operation restarts. In this
case, the transfer count register operates in free-running mode, so that transfer operation is
continued until the transfer enable bit is set to 0 (to disable transfer). No DMA transfer-finished
interrupts are generated.
(2) TREQFn (DMAn transfer request flag) bit (D1)
This flag is set to 1 when a DAM transfer request occurs. Reading this flag helps to know whether
there is a DMA transfer request on any channel.
The DMA transfer request is cleared by writing 0 to this bit. Writing 1 has no effect, the bit retains
the value it had before writing.
Even when a new DMA transfer request occurs for a channel whose DMA transfer request flag is
already set to 1, the next DMA transfer request is not accepted until after a transfer on the
channel is completed.
(3) REQSLn (cause of DMAn request select) bits (D2, D3)
These bits select the cause of DMA request on each DMA channel.
Note: If "Extended request cause" is selected for the cause of DMA request, always be sure to
set the DMA Request Extended Cause Register to select a DMA request extended
cause.
(4) TENLn (DMAn transfer enable) bit (D4)
Setting this bit to 1 enables transfer, making a DMA transfer ready to run. Setting this bit to 0
disables transfer. However, if a transfer request has already been accepted, transfer is not
disabled until after the requested transfer is completed.
(5) TSZSLn (DMAn transfer size select) bit (D5)
This bit selects the number of data bits to be transferred in one DMA transfer operation (unit of
one transfer). The unit of one transfer is 16 bits when this bit = 0, or 8 bits when this bit = 1.
(6) SADSLn (DMAn source address direction select) bit (D6)
This bit selects the direction in which the source address changes from two modes available:
address fixed or address increment.
(7) DADSLn (DMAn destination address direction select) bit (D7)
This bit selects the direction in which the destination address changes from two modes available:
address fixed or address increment.
DMAC
9.2 DMAC Related Registers
Содержание 32172
Страница 20: ... This is a blank page 16 ...
Страница 21: ...1 1 Overview 1 2 Block Diagram 1 3 Pin Functions 1 4 Pin Layout CHAPTER 1 CHAPTER 1 OVERVIEW ...
Страница 44: ...1 1 24 Rev 1 0 This is a blank page Overview 1 4 Pin Layout ...
Страница 58: ...2 2 14 Rev 1 0 This is a blank page CPU 2 6 Data Formats ...
Страница 122: ...4 4 26 Rev 1 0 This is a blank page EIT 4 13 Precautions on EIT ...
Страница 200: ...7 7 6 Rev 1 0 This is a blank page RESET 7 4 Precautions to Be Taken Immediately after Reset ...
Страница 240: ...8 8 40 Rev 1 0 This is a blank page INPUT OUTPUT PORTS AND PIN FUNCTIONS 8 5 Precautions on Input Output Ports ...
Страница 298: ...9 9 58 Rev 1 0 This is a blank page DMAC 9 4 Precautions on Using DMAC ...
Страница 416: ...10 10 118 Rev 1 0 This is a blank page INPUT OUTPUT TIMERS 10 6 TOM Output Related 16 bit Timers ...
Страница 658: ...14 14 16 Rev 1 0 REAL TIME DEBUGGER RTD 14 4 Typical Connection with the Host This is a blank page ...
Страница 718: ...16 16 16 Rev 1 0 This is a blank page D A CONVERTERS 16 3 Functional Description of the D A Converters ...
Страница 766: ...18 18 22 Rev 1 0 WAIT CONTROLLER 18 3 Typical Operation of the Wait Controller This is a blank page ...
Страница 776: ...19 19 10 Rev 1 0 RAM BACKUP MODE 19 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Страница 777: ...CHAPTER 20 CHAPTER 20 OSCILLATION CIRCUIT 20 1 Oscillator Circuit 20 2 Clock Generator Circuit ...
Страница 782: ...20 20 6 Rev 1 0 OSCILLATION CIRCUIT 20 2 Clock Generator Circuit This is a blank page ...
Страница 856: ...23 23 26 Rev 1 0 This is a blank page ELECTRICAL CHARACTERISTICS 23 6 AC Characteristics ...
Страница 857: ...24 1 A D Conversion Characteristics CHAPTER 24 CHAPTER 24 STANDARD CHARACTERISTICS ...
Страница 859: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Страница 861: ...Appendix 2 1 M32R E Instruction Processing Time APPENDIX 2 APPENDIX 2 INSTRUCTION PROCESSING TIME ...
Страница 865: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...