
ML62Q1000 Series User's Manual
Chapter 14
DMA
Controller
FEUL62Q1000
14-15
14.3.2 DMA transfer Operation Timing Diagram
The following chart shows an operation timing diagram with the transfer source set to RAM/increment addressing,
transfer destination to SFR/fixed address, transfer unit to 8-bit, and transfer count to twice.
1.
Set DCnEN of the DMA enable register (DCEN) to "1" to enable transfer. When a transfer trigger is generated, the
transfer automatically starts.
2.
Once the DMA transfer has been performed up to the number of times set in the DMA channel n transfer count
register (DCnTNn), the DMA interrupt (DMAINT) request is generated.
3.
Read the DCnISTA bit of the DMA status register (DSTAT) to find the channel in which the transfer is completed
and write "1" to the DICLRn bit to clear the DCnISTA bit.
Figure 14-5 Operation Timing Diagram
(transfer source=RAM/increment addressing, transfer destination=SFR/fixed address,
transfer unit=8-bit, transfer count=twice)
[Note]
•
CPU data memory access is processed in priority to the DMA transfer.
Successive CPU data memory access may cause the DMA transfer to be held, resulting in the transfer
trigger overwritten. Prevent successive CPU data memory access from continuing for longer than the
transfer trigger generation cycle.
If CPU data memory access is not performed, ensure that the interval of four clocks of the system clock
is secured.
•
If a transfer trigger and the software trigger are generated at the same time, the transfer trigger is
overwritten. Pay attention to the timing the software trigger is generated.
•
Specify an area where the RAM and SFR exist for the transfer source address and destination address. If
the area that does not exist in the transfer source address is set, data "0x00" is transferred. If the area
that does not exist in the transfer destination address is set, it is invalid.
DCnEN
2
SYSTEMCLK
DMAINT
Transfer trigger
RAM
Addr
Address
Transfer count
register (DCnTN)
1
0
DCnISTA
Write "1" to DICLRn to clear DCnISTA bit
n=0,1
SFR
Addr
RAM
Addr
SFR
Addr
Address X
Address Y
Address X+1
Address Y
Содержание ML62Q1000 Series
Страница 17: ...Chapter 1 Overview...
Страница 112: ...Chapter 2 CPU and Memory Space...
Страница 154: ...Chapter 3 Reset Function...
Страница 166: ...Chapter 4 Power Management...
Страница 196: ...Chapter 5 Interrupts...
Страница 248: ...Chapter 6 Clock generation Circuit...
Страница 274: ...Chapter 7 Low Speed Time Base Counter...
Страница 291: ...Chapter 8 16 Bit Timer...
Страница 320: ...Chapter 9 Functional Timer FTM...
Страница 382: ...Chapter 10 Watchdog Timer...
Страница 402: ...Chapter 11 Serial Communication Unit...
Страница 456: ...Chapter 12 I2 C Bus Unit...
Страница 491: ...Chapter 13 I2 C Master...
Страница 512: ...Chapter 14 DMA Controller...
Страница 531: ...Chapter 15 Buzzer...
Страница 550: ...Chapter 16 Simplified RTC...
Страница 559: ...Chapter 17 GPIO...
Страница 594: ...Chapter 18 External Interrupt Function...
Страница 612: ...Chapter 19 CRC Generator...
Страница 632: ...Chapter 20 Analog Comparator...
Страница 644: ...Chapter 21 D A Converter...
Страница 655: ...Chapter 22 Voltage Level Supervisor...
Страница 676: ...Chapter 23 Successive Approximation Type A D Converter...
Страница 709: ...Chapter 24 Regulator...
Страница 714: ...Chapter 25 Flash Memory...
Страница 743: ...Chapter 26 Code Option...
Страница 750: ...Chapter 27 LCD Driver...
Страница 788: ...Chapter 28 On Chip Debug Function...
Страница 795: ...Chapter 29 Safety Function...
Страница 813: ...Appendix A...
Страница 881: ...Revision History...