TX4939XBG-400 Toshiba, TX4939XBG-400 Datasheet - Page 292

• Manufacturer Part Number: TX4939XBG-400
• Manufacturer: Toshiba

Specifications of TX4939XBG-400

• Cpu Core: TX49/H4 90nm
• Clock Mhz/max Mips: 400/520
• Inst./data Cache: 32KB (4 Way)/32KB (4 Way)
• Tlb: x
• 1cycle Mac: x
• Volts (v): 1.25/2.5/3.3
• Peripherals: DDR, NAND, ATA, ETHERNET, SECURITY, FPU, MMU, SPI, I2S, I2C, PCI, VIDEO, UART, TIMER, RTC
• Companion Chip: TC86C001FG
• Package: PGBA456

DMA
14.3. Detailed Explanation
14.3.1. Transfer Mode
The DMA Controller (DMAC0, DMAC1) supports five transfer mode types (refer to Table 14-1 DMA Controller Transfer
Modes 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/I2S or SIO or NDFMC)
Memory Transfer Mode (DMCCRn.EXTRQ = “0”)
Either copies data between memory devices or fills data in memory.
14.3.2. On-chip Registers
The DMA Controller has two shared registers that are shared by four channels. Section 0 explains each register in detail.
Rev. 3.1 November 1, 2005
DMA
Controller
DMAC0
DMAC1
Shared Registers
DMMCR:
DMMFDR:
DMA Channel Register
DMCHARn:
DMSARn:
DMDARn:
DMCNTRn:
DMSAIRn:
DMDAIRn:
DMCCRn:
DMCSRn:
Transfer Mode
External I/O
(Dual Address)
Internal I/O (SIO)
Internal- I/O (NDFMC)
Memory-Memory Copy
Internal I/O (ACLC/I2S)
Memory-Memory Copy
Table 14-1 DMA Controller Transfer Modes
DMCCRn
EXTREQ
1
1
1
0
1
0
PCFG
DMASEL
DMA Master Control Register
DMA Memory Fill Data Register
DMA Chained Address Register
DMA Source Address Register
DMA Destination Address Register
DMA Count Register
DMA Source Address Increment Register
DMA Destination Address Increment Register
DMA Channel Control Register
DMA Channel Status Register
14-4
⎯
⎯
⎯
0
1
1
DMCCRn
SNGAD
0
0
1
0
0
0
DMSAR
Toshiba RISC Processor
√
√
√
√
√
√
DMDAR
√
√
√
√
√
Ref.
TX4939
14.3.3
14.3.8
14.3.4
14.3.8
14.3.4
14.3.4
14.3.8
14.3.4
14.3.8
14.3.4
14.3.8
14
14