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Chapter 26 DMA Controller
3.DMA Controller (DMAC) Operation
Even if DREQ is reasserted earlier, it is ignored because the transfer has not been completed. If no transfer
requests for other channels occur, transfer over the same channel is restarted by reasserting DREQ when the
DACK pin output is asserted.
■
Timing of DACK Pin Output
The DACK output of this DMAC indicates that transfer with respect to an accepted transfer request is being
performed.
The output of DACK is basically synchronized with the address output of external bus access timing. To use
DACK output, it is necessary to enable the DACK output with a port.
■
Timing of the DEOP Pin Output
•
The DEOP output of this DMA indicates that DMA transfer for the specified number of times of the accepted
channel has been completed.
•
DEOP output is output when access to an external area of the last transfer block starts. Thus, if any value
other than 1 is set (block transfer mode) as the block size, DEOP is output when the last data of the last block
is transferred. In this case, the acceptance of the next DREQ is already started even during transfer (before
DEOP output) if the DACK pin output is asserted.
•
The DEOP output is synchronized with RD and WRn of external bus access timing. However, if the transfer
source/transfer destination is internal access, DEOP is not output. To use DEOP output, it is necessary to
enable the DEOP output using the port register.
■
If an External Pin Transfer Request is Reentered During Transfer
●
For burst, step, and block transfers
While the DACK signal is asserted within the DMAC, the next transfer request, if it is entered, is disabled.
However, since operation of the external bus control unit and operation of the DMAC are not completely
synchronous, the circuit must be initialized to create DREQ pin input using DACK and DEOP output to enable
transfer requests by using DREQ input.
●
For a demand transfer
If reloading of the transfer count register is specified when transfer for as many transfers as specified has been
completed, another transfer request is accepted.
■
If Another Transfer Request Occurs During Block Transfer
No request is detected before the transfer of the specified blocks is completed. At the block boundaries, transfer
requests accepted at that time are evaluated and then transfer on the channel with the highest priority is
performed.
■
Transfer Between External I/O and External Memory
As targets of transfer by the DMAC, external I/O and external memory are not distinguished. Specify an external
I/O as a fixed external address.
To perform fly-by transfer, set the address of external memory in the transfer destination address register. For
external I/O, use DACK output and the signal decoded by the read signal RD or write signal WRn pin.
Summary of Contents for FR Family FR60 Lite
Page 2: ...FUJITSU LIMITED ...
Page 3: ...FR60 32 BIT MICROCONTROLLER MB91460 Series User s Manual ...
Page 15: ...xi ...
Page 16: ...xii ...
Page 38: ...22 Chapter 2 MB91460 Rev A Rev B Overview 4 Block Diagram ...
Page 128: ...112 Chapter 4 CPU Architecture 9 Addressing ...
Page 153: ...137 Chapter 8 Device State Transition 3 State Transition Diagram ...
Page 154: ...138 Chapter 8 Device State Transition 3 State Transition Diagram ...
Page 169: ...153 Chapter 9 Reset 10 Caution ...
Page 170: ...154 Chapter 9 Reset 10 Caution ...
Page 180: ...164 Chapter 10 Standby 7 Q A ...
Page 182: ...166 Chapter 10 Standby 8 Caution ...
Page 199: ...183 Chapter 12 Instruction Cache 2 Main body structure Figure 2 3 I Cache Address Map ...
Page 200: ...184 Chapter 12 Instruction Cache 2 Main body structure Figure 2 4 I Cacheable Area ...
Page 222: ...206 Chapter 13 Clock Control 8 Caution ...
Page 232: ...216 Chapter 14 PLL Interface 7 Caution ...
Page 236: ...220 Chapter 15 CAN Clock Prescaler 3 Registers ...
Page 288: ...272 Chapter 19 Timebase Timer 8 Caution ...
Page 314: ...298 Chapter 22 Main Oscillation Stabilisation Timer 8 Caution ...
Page 326: ...310 Chapter 23 Sub Oscillation Stabilisation Timer 8 Caution ...
Page 348: ...332 Chapter 25 External Interrupt 8 Caution ...
Page 398: ...382 Chapter 26 DMA Controller 6 DMA External Interface ...
Page 402: ...386 Chapter 27 Delayed Interrupt 8 Caution ...
Page 412: ...396 Chapter 28 Bit Search 8 Caution ...
Page 521: ...505 Chapter 30 I O Ports 3 Port Register Settings ...
Page 522: ...506 Chapter 30 I O Ports 3 Port Register Settings ...
Page 574: ...558 Chapter 31 External Bus 4 Endian and Bus Access Byte Access ...
Page 628: ...612 Chapter 31 External Bus 13 Notes on Using the External Bus Interface ...
Page 706: ...690 Chapter 33 I2C Controller 4 Programming Flow Charts ...
Page 748: ...732 Chapter 34 CAN Controller 4 CAN Application ...
Page 762: ...746 Chapter 35 Free Run Timer 8 Caution ...
Page 790: ...774 Chapter 37 Output Compare 8 Caution ...
Page 838: ...822 Chapter 39 Programmable Pulse Generator 8 Caution ...
Page 850: ...834 Chapter 40 Pulse Frequency Modulator 4 PFM Operation and Setting ...
Page 886: ...870 Chapter 42 Sound Generator 3 Registers ...
Page 900: ...884 Chapter 43 Stepper Motor Controller 4 Caution ...
Page 939: ...923 Chapter 47 LCD Controller 3 Configuration Figure 3 2 Register List ...
Page 943: ...927 Chapter 47 LCD Controller 4 Registers Correspondence between VRAM and Common Segment Pins ...
Page 964: ...948 Chapter 48 Clock Monitor 8 Caution ...
Page 994: ...978 Chapter 51 Low Voltage Reset Interrupt 3 Registers ...
Page 998: ...982 Chapter 52 Regulator Control 3 Registers ...
Page 1008: ...992 Chapter 53 Fixed Mode Reset Vector BOOT ROM 5 Bootloader Update Strategy ...
Page 1024: ...1008 Chapter 54 Flash Memory 8 Caution ...
Page 1032: ...1016 Chapter 55 Flash Security 4 Register ...
Page 1034: ...1018 Chapter 56 Electrical Specification ...
Page 1035: ...FR60 MB91460 Series Hardware Manual European Microcontroller Design Centre Author MBo ...
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