Motorola MCF5282 Source Address Registers SAR0-SAR3, Destination Address Registers DAR0-DAR3, Sar

Models: MCF5282 MCF5281

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DMA Controller Module Programming Model

16.4.1 Source Address Registers (SAR0–SAR3)

SARn, shown in Figure 16-4,contains the address from which the DMA controller requests data.

Field

Reset

R/W

Address

31

0

SAR

0000_0000_0000_0000_0000_0000_0000_0000

R/W

IPSBAR + 0x100, 0x140, 0x180, 0x1C0

Figure 16-4. Source Address Registers (SARn)

NOTE

The backdoor enable bit must be set in both the core and SCM in order to enable backdoor accesses from the DMA to SRAM. See Section 8.4.2, “Memory Base Address Register (RAMBAR)” for more details.

NOTE

Flash accesses (reads/writes) by a bus master other than the core (DMA controller or Fast Ethernet Controller), or writes to Flash by the core during programming, must use the backdoor Flash address of IPSBAR plus an offset of 0x0400_0000. For example, for a DMA transfer from the first Flash location when IPSBAR is still at its default location of 0x4000_0000, the source register would be loaded with 0x4400_0000. Backdoor Flash read accesses can be made with the bus master, but it takes two cycles longer than a direct read of the Flash when using the FLASHBAR address.

16.4.2 Destination Address Registers (DAR0–DAR3)

DARn, shown in Figure 16-5,holds the address to which the DMA controller sends data.

Field

Reset

R/W Address

31

0

DAR

0000_0000_0000_0000_0000_0000_0000_0000

R/W

IPSBAR + 0x104, 0x144, 0x184, 0x1C4

Figure 16-5. Destination Address Registers (DARn)

16-6

MCF5282 User’s Manual

MOTOROLA

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Motorola MCF5282, MCF5281 user manual Source Address Registers SAR0-SAR3, Destination Address Registers DAR0-DAR3, Sar, Dar