Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet

Product codes
AT91SAM9N12-EK
Page of 1104
460
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
32.
DMA Controller (DMAC)
32.1
Description
The DMA Controller (DMAC) is an AHB-central DMA controller core that transfers data from a source peripheral to a
destination peripheral over one or more AMBA buses. One channel is required for each source/destination pair. In the
most basic configuration, the DMAC has one master interface and one channel. The master interface reads the data from
a source and writes it to a destination. Two AMBA transfers are required for each DMAC data transfer. This is also known
as a dual-access transfer.
The DMAC is programmed via the APB interface.
32.2
Embedded Characteristics
2 AHB-Lite Master Interfaces
DMA Module Supports the Following Transfer Schemes: Peripheral-to-Memory, Memory-to-Peripheral, Peripheral-
to-Peripheral and Memory-to-Memory
Source and Destination Operate independently on BYTE (8-bit), HALF-WORD (16-bit) and WORD (32-bit)
Supports Hardware and Software Initiated Transfers
Supports Multiple Buffer Chaining Operations
Supports Incrementing/decrementing/fixed Addressing Mode Independently for Source and Destination
Supports Programmable Address Increment/decrement on User-defined Boundary Condition to Enable Picture-in-
Picture Mode
Programmable Arbitration Policy, Modified Round Robin and Fixed Priority are Available
Supports Specified Length and Unspecified Length AMBA AHB Burst Access to Maximize Data Bandwidth
AMBA APB Interface Used to Program the DMA Controller
8 DMA Channels 29 External Request Lines 
Embedded FIFO 
Channel Locking and Bus Locking Capability