Chapter 8 DMA Controller
8-3
8.3 Detailed
Explanation
8.3.1 Transfer
Mode
The DMA Controller supports five transfer mode types (refer to Table 8.3.1 below). The setting of the
External Request bit (DMCCRn.EXTRQ) of the DMA Channel Control Register selects whether
transfer with an I/O device is a DMA transfer.
•
I/O DMA Transfer Mode (DMCCRn.EXTRQ = “1”)
Perform DMA transfer with either an external device connected to the External Bus Controller or
an on-chip I/O device (ACLC or SIO).
•
Memory Transfer Mode (DMCCRn.EXTRQ = “0”)
Either copies data between memory devices or fills data in memory.
Table 8.3.1 DMA Controller Transfer Modes
Transfer Mode
DMCCRn
EXTREQ
DRQCTR
DMAREQn
DMCCRn
SNGAD
DMSAR DMDAR Ref.
External I/O
(Single Address)
1 0xxxx 1
√
-
8.3.3
8.3.7
External I/O
(Dual Address)
1 0xxxx 0
√
√
8.3.3
8.3.8
Internal I/O
1
10xx (SIO)
11xx (ACLC)
0
√
√
8.3.4
8.3.8
Memory-Memory Copy
0
-
0
√
√
8.3.4
8.3.8
Fill Memory
0
-
1
√
-
8.3.6
8.3.7
8.3.2 On-chip
Registers
The DMA Controller has two shared registers that are shared by four channels. Section 8.4 explains
each register in detail.
•
Shared Registers
DMMCR:
DMA Master Control Register
DMMFDR:
DMA Memory Fill Data Register
•
DMA Channel Register
DMCHARn:
DMA Chained Address Register
DMSARn:
DMA Source Address Register
DMDARn: DMA
Destination
Address
Register
DMCNTRn: DMA
Count
Register
DMSAIRn:
DMA Source Address Increment Register
DMDAIRn:
DMA Destination Address Increment Register
DMCCRn:
DMA Channel Control Register
DMCSRn:
DMA Channel Status Register
Summary of Contents for TMPR4925
Page 1: ...64 Bit TX System RISC TX49 Family TMPR4925 Rev 3 0 ...
Page 4: ......
Page 15: ...Handling Precautions ...
Page 16: ......
Page 18: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 40: ...3 General Safety Precautions and Usage Considerations 3 18 ...
Page 42: ...4 Precautions and Usage Considerations 4 2 ...
Page 43: ...TMPR4925 ...
Page 44: ......
Page 54: ...Chapter 1 Features 1 8 ...
Page 58: ...Chapter 2 Block Diagram 2 4 ...
Page 88: ...Chapter 4 Address Mapping 4 12 ...
Page 226: ...Chapter 8 DMA Controller 8 58 ...
Page 260: ...Chapter 9 SDRAM Controller 9 34 ...
Page 480: ...Chapter 15 Interrupt Controller 15 32 ...
Page 554: ...Chapter 19 Real Time Clock RTC 19 8 ...
Page 555: ...Chapter 20 Removed 20 1 20 Removed ...
Page 556: ...Chapter 20 Removed 20 2 ...
Page 564: ...Chapter 21 Extended EJTAG Interface 21 8 ...
Page 580: ...Chapter 22 Electrical Characteristics 22 16 ...
Page 588: ...Chapter 24 Usage Notes 24 2 ...