Datasheet

SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
478
Figure 26-7. DMAC Transfer Flow for Source and Destination Linked List Address
Multi-buffer DMAC Transfer with Linked List for Source and Contiguous Destination Address (Row 2)
1. Read the Channel Handler Status register to choose a free (disabled) channel.
2. Set up the linked list in memory. Write the control information in the LLI.DMAC_CTRLAx and
LLI.DMAC_CTRLBx register location of the buffer descriptor for each LLI in memory for channel x. For
example, in the register, you can program the following:
Channel enabled by
software
LLI Fetch
Hardware reprograms
SADDRx, DADDRx, CTRLA/Bx, DSCRx
DMAC buffer transfer
Writeback of DMAC_CTRLAx
register in system memory
Is DMAC in
Row 1 of
DMAC State Machine Table?
Channel disabled by
hardware
Chained Buffer Transfer Completed
Interrupt generated here
DMAC Chained Buffer Transfer
Completed Interrupt generated here
yes
no