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CHAPTER 17 DMA CONTROLLER
descriptor together with the DMACT value.
8. The bus right is returned to the CPU.
9. DACSR DEDn is set to 1, and a CPU interrupt is generated if interrupts are enabled.
If the descriptor is stored in the internal RAM, and data of byte length is transferred between
external buses, the required minimum cycle count per transfer is as described below, under the
conditions indicated:
•
When both the transfer source and destination addresses are fixed: (6 + 5 x n) cycles
•
When only one of the transfer source and destination addresses is fixed: (7 + 5 x n) cycles
•
When both the transfer source and destination addresses are incremented or decremented:
(8 + 5 x n) cycles
■
Combinations of request sense modes and transfer modes
Figure 17.4-1 "Combinations of request sense modes and transfer modes" shows the available
combinations of request sense modes and transfer modes.
Figure 17.4-1 Combinations of request sense modes and transfer modes
■
DREC signal sense modes
❍
Edge sense
This mode can be used in step transfer (single/block) and burst transfer modes.
DMA requests are detected at an active edge.
Because the input of an external DREQ is masked during DMAC transfer, note that the active
edge for the next transfer must be after that of the transfer destination DACK in the previous
DMA transfer.
❍
Level sense
This mode can be used in step transfer (single/block) and continuos and burst transfer modes.
DMA requests are detected at an "active" level.
Note:
min 2tCYC [ns] applies as the electrical characteristic of DACK signals for both level and
edge detection.
In the case of edge detection, min 2tCYC [ns] is also required as DACK negation interval.
Request sense
Edge sense
Level sense
Burst transfer
mode
Continuos
transfer mode
Step operation
mode
Single transfer
Block transfer
Transfer mode
Transfer unit
Содержание MB91150 Series
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Страница 3: ...FUJITSU LIMITED FR30 32 BIT MICROCONTROLLER MB91150 Series HARDWARE MANUAL ...
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Страница 10: ...vi ...
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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