AN2168 Freescale Semiconductor / Motorola, AN2168 Datasheet - Page 5

• Manufacturer Part Number: AN2168
• Description: ColdFire Microprocessor DMA Controller Application Note
• Manufacturer: Freescale Semiconductor / Motorola

Dual and Single Address Modes
Dual Address
Mode
Dual Address Mode
Example 1
AN2168
MOTOROLA
CSAR0 = 0xFFE0 ; base address = 0xFFE00000
CSMR0 = 0x000F0001 ; address range = 0xFFE00000-FFEFFFFF
CSCR0 = 0x0D80 ; 3 wait states, auto-acknowledge, 16-bit port
CSAR1 = 0x2000 ; base address = 0x20000000
CSMR1 = 0x00000001 ; address range = 0x20000000-2000FFFF
CSCR1 = 0x0158 ; 0 waitstates, autoacknowledge, 8-bit port, burst enabled
DSR = 0x01 ; clear status register
SAR = 0xFFE00400 ; source address = 0xFFE00400
DAR = 0x20000000 ; destination address = 0x20000000
BCR = 0x002 ; transfer 2 bytes
DCR = 0x006B ; source = 16-bit, destination = 8-bit
The DMA controller has two primary transfer modes:
Dual address mode is the most straightforward DMA transfer mode to
implement. A dual address transfer consists of two phases. There is at
least one read from the source address followed by one or more writes
to the destination address. The number of reads and writes will depend
on the source and destination sizes programmed in the DMA control
register (DCR) as well as the port size for the source and destination
address.
For example, the MCF5307 is programmed with the following chip select
parameters:
The DMA is programmed with the following values:
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Dual address
Single address
Dual and Single Address Modes
Application Note
5