ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 1028

• Manufacturer Part Number: ATSAM3U-EK
• Description: KIT EVAL FOR AT91SAM3U CORTEX
• Manufacturer: Atmel
• Type: MCUr

Specifications of ATSAM3U-EK

• Contents: Board
• Processor To Be Evaluated: SAM3U
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3 V
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: SAM3U4E
• Silicon Family Name: SAM3U
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT91SAM3U
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 40-8. DMAC Transfer with Linked List Source Address and Contiguous Destination Address
1028
SAM3U Series
Source Layer
Address of
SADDR(1)
SADDR(0)
SADDR(2)
Note:
The DMAC transfer might look like that shown in
nation address is decrementing.
The DMAC transfer flow is shown in
15. Once the buffer of data is transferred, the DMAC_CTRLAx register is written out to sys-
16. The DMAC does not wait for the buffer interrupt to be cleared, but continues and
tem memory at the same location and on the same layer (DMAC_DSCRx.DSCR_IF)
where it was originally fetched, that is, the location of the DMAC_CTRLAx register of
the linked list item fetched prior to the start of the buffer transfer. Only DMAC_CTRLAx
register is written out because only the DMAC_CTRLAx.BTSIZE and
DMAC_CTRLAX.DONE fields have been updated by DMAC hardware. Additionally, the
DMAC_CTRLAx.DONE bit is asserted when the buffer transfer has completed.
fetches the next LLI from the memory location pointed to by current DMAC_DSCRx
register and automatically reprograms the DMAC_SADDRx, DMAC_CTRLAx,
DMAC_CTRLBx and DMAC_DSCRx channel registers. The DMAC_DADDRx register
is left unchanged. The DMAC transfer continues until the DMAC samples the
DMAC_CTRLAx, DMAC_CTRLBx and DMAC_DSCRx registers at the end of a buffer
transfer match that described in Row 1 of
knows that the previous buffer transferred was the last buffer in the DMAC transfer.
Do not poll the DMAC_CTRLAx.DONE bit in the DMAC memory map. Instead, poll the
LLI.DMAC_CTRLAx.DONE bit in the LLI for that buffer. If the poll LLI.DMAC_CTRLAx.DONE bit is
asserted, then this buffer transfer has completed. This LLI.DMAC_CTRLAx.DONE bit was cleared
at the start of the transfer.
Source Buffers
Buffer 0
Buffer 1
Buffer 2
Figure 40-9 on page
Destination Buffers
Buffer 0
Buffer 2
Buffer 1
Table 40-1 on page
Figure 40-8 on page 1028
1029.
DADDR(2)
DADDR(1)
DADDR(0)
Destination Layer
1020. The DMAC then
Address of
6430D–ATARM–25-Mar-11
Note that the desti-