332
CHAPTER 15 DMAC
15.5 Descriptor Register in RAM
This descriptor register has the setup information for the corresponding channel in
DMA transfer mode.
The descriptor register has a 12-byte area for each channel that is allocated to the
memory address specified by DPDP.
See Table 15.2-1, " Channel descriptor addresses," for the first address of the
descriptor for each channel.
■
First Word of a Descriptor
The structure of the first word of a descriptor is shown below.
[bits 31 to 16] DMACT: Transfer count
These bits specify the number of times DMA transfer is to be performed. When 0000H is
specified, DMA transfer is performed 65,536 times.
The value is decremented by 1 each time DMA transfer is performed.
[bits 15 to 12] Reserved
[bits 11 to 8] BLK: Block size specification
These bits specify the size of blocks to be transferred in single/block transfer mode.
When 0 is specified, a block size of 16 is assumed.
Specify 1 for single transfer.
[bits 7, 6] SCS1, SCS0: Transfer source address update mode
31
16
R/W
15
14
13
12
11
10
9
8
R/W
7
6
5
4
3
2
1
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
DMACT
DCS0
DCS1
SCS0
SCS1
WS0
MOD1
WS1
BLK
MOD0
Initial value: undefined
Summary of Contents for MB91F109
Page 2: ......
Page 3: ...FUJITSU LIMITED FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...
Page 4: ......
Page 10: ...vi ...
Page 24: ...xx ...
Page 96: ...72 CHAPTER 2 CPU ...
Page 224: ...200 CHAPTER 4 BUS INTERFACE ...
Page 234: ...210 CHAPTER 5 I O PORTS ...
Page 268: ...244 CHAPTER 9 U TIMER ...
Page 290: ...266 CHAPTER 10 UART ...
Page 314: ...290 CHAPTER 12 16 BIT RELOAD TIMER ...
Page 322: ...298 CHAPTER 13 BIT SEARCH MODULE ...
Page 392: ...368 CHAPTER 16 FLASH MEMORY ...
Page 432: ...408 APPENDIX E Instructions F Table E 2 Instruction Formats OP rel11 5 11 ...
Page 448: ...424 APPENDIX E Instructions ...
Page 449: ...425 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 458: ...434 INDEX ...
Page 460: ......
Page 461: ...FUJITSU SEMICONDUCTOR FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...