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CHAPTER 17 DMA CONTROLLER
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Notes on edge mode
In edge sense mode, the next DREQ edge must be input after the clearance point of the DMAC
request flag. Any edge input before that point is ignored.
To ensure the edge is recognized, a negation interval of min 2tCYC [ns] is required.
Input the DREQ, as shown in Figure 17.4-6 "Edge-mode timing", after the falling DACK edge
during transfer destination access.
Figure 17.4-6 "Edge-mode timing" Shows the timing in edge-mode.
Figure 17.4-6 Edge-mode timing
CLK
DREQ
DACK
Internal
D-Abus
external
A bus
A
B
DREQ(NG)
DREQ(NG)
DREQ(NG)
Writing to destination
Active edge is too early.
The time is greater than
"Min 2tCYC [ns]"
Descriptor writing
Transfer
destination
Transfer
destination
A:
Request flag clearance point
Sensing start point for the next DREQ in edge sense mode
Sensing start point for the next DREQ in continuous transfer mode
B:
Sensing start point for the next DREQ during single and block transfer in level sense mode
Note: The timing from DREQ to DMA start reflects the case where this is performed close to top speed.
Содержание MB91150 Series
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Страница 3: ...FUJITSU LIMITED FR30 32 BIT MICROCONTROLLER MB91150 Series HARDWARE MANUAL ...
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Страница 112: ...96 CHAPTER 3 MEMORY SPACE CPU AND CONTROL UNIT ...
Страница 174: ...158 CHAPTER 5 I O PORTS Note DDRI bit 6 is a test bit Always set the bit to 0 The value read from this bit is always 0 ...
Страница 178: ...162 CHAPTER 5 I O PORTS ...
Страница 214: ...198 CHAPTER 7 16 BIT RELOAD TIMER ...
Страница 240: ...224 CHAPTER 8 PPG TIMER ...
Страница 310: ...294 CHAPTER 13 8 10 BIT A D CONVERTER ...
Страница 318: ...302 CHAPTER 14 8 BIT D A CONVERTER ...
Страница 362: ...346 CHAPTER 15 UART ...
Страница 420: ...404 CHAPTER 19 PERIPHERAL STOP CONTROL ...
Страница 428: ...412 CHAPTER 20 CALENDAR MACROS ...
Страница 503: ...487 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
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