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Rev.1.0
9.3 Functional Description of DMAC
9.3.1 Cause of DMA Request
A DMA transfer can be requested individually for each DMA channel (0-9 channels) from multiple
sources. There are various causes of DMA transfer request, so that a DMA transfer may be started
by an internal peripheral I/O, started in software by a program, or started by completion of one or all
DMA transfers on another channel (cascade mode).
To select a cause of DMA request, use the cause of request select bits for the desired channel
REQSLn (DMAn Channel Control Register D2, D3 bits) or the extended request cause select bits
REQESELn (DMAn Request Extended Cause Register D4-D7 bits). The causes of DMA request
on each channel are listed below.
Table 9.3.1 Causes of DMA Request on DMA0 and the Timing at Which Requests are Generated
REQSL0
Causes of DMA Request
DMA Request Generation Timing
0 0
Software start or
When any data is written to the DMA0 Software Request
One DMA2 transfer completed
Generation Register (software start) or one transfer on
DMA2 is completed (cascade mode)
0 1
A-D0 conversion completed
When A-D0 conversion is completed
1 0
Timer (TOM00_udf)
When TOM00 timer underflows
1 1
Extended request cause
–
Table 9.3.2 DMA Request Extended Causes on DMA0 and the Timing at Which Requests are Generated
REQESEL0
DMA Request Extended Cause
DMA Request Generation Timing
0000
All DMA1 transfers completed
When all transfers on DMA1 are completed (cascade mode)
0001
TID0_udf,ovf
When TID0 timer underflows or overflows
0010
TID1_udf,ovf
When TID1 timer underflows or overflows
0011
TIN16 input signal
When the timer's TIN16 input signal is generated
0100
TIN0A input signal
When PD module's TIN0A input signal is generated
0101
Serial I/O-2
When serial I/O-2 transmit buffer is empty
(transmit buffer empty)
0110
Serial I/O-7
When serial I/O-7 transmit buffer is empty
(transmit buffer empty)
Note: The DMA request extended causes are effective only when "Extended request cause" is selected with
the DMA0 Channel Control Register REQSL0 bits.
DMAC
9.3 Functional Description of DMAC
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 ...