ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 1022

• 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

40.3.5.3
1022
SAM3U Series
Multi-buffer Transfer with Linked List for Source and Linked List for Destination (Row 4)
4. After the DMAC selected channel has been programmed, enable the channel by writing
5. Source and destination request single and chunk DMAC transactions to transfer the
6. Once the transfer completes, hardware sets the interrupts and disables the channel. At
1. Read the Channel Enable register to choose a free (disabled) channel.
2. Set up the chain of Linked List Items (otherwise known as buffer descriptors) in mem-
3. Write the channel configuration information into the DMAC_CFGx register for channel
4. Make sure that the LLI.DMAC_CTRLBx register locations of all LLI entries in memory
5. Make sure that the LLI.DMAC_DSCRx register locations of all LLI entries in memory
6. Make sure that the LLI.DMAC_SADDRx/LLI.DMAC_DADDRx register locations of all
a ‘1’ to the DMAC_CHER.ENABLE[n] bit, where n is the channel number. Make sure
that bit 0 of DMAC_EN.ENABLE register is enabled.
buffer of data (assuming non-memory peripherals). The DMAC acknowledges at the
completion of every transaction (chunk and single) in the buffer and carry out the buffer
transfer.
this time you can either respond to the buffer Complete or Transfer Complete interrupts,
or poll for the Channel Handler Status Register (DMAC_CHSR.ENABLE[n]) bit until it is
cleared by hardware, to detect when the transfer is complete.
ory. Write the control information in the LLI.DMAC_CTRLAx and LLI.DMAC_CTRLBx
registers location of the buffer descriptor for each LLI in memory (see
page
a. Set up the transfer type (memory or non-memory peripheral for source and desti-
b. Set up the transfer characteristics, such as:
– i. Transfer width for the source in the SRC_WIDTH field.
– ii. Transfer width for the destination in the DST_WIDTH field.
– v. Incrementing/decrementing or fixed address for source in SRC_INCR field.
– vi. Incrementing/decrementing or fixed address for destination DST_INCR field.
x.
a. Designate the handshaking interface type (hardware or software) for the source
b. If the hardware handshaking interface is activated for the source or destination
(except the last) are set as shown in Row 4 of
LLI.DMAC_CTRLBx register of the last Linked List Item must be set as described in
Row 1 of
list items.
(except the last) are non-zero and point to the base address of the next Linked List
Item.
LLI entries in memory point to the start source/destination buffer address preceding
that LLI fetch.
nation) and flow control device by programming the FC of the DMAC_CTRLBx
register.
and destination peripherals. This is not required for memory. This step requires pro-
gramming the SRC_H2SEL/DST_H2SEL bits, respectively. Writing a ‘1’ activates
the hardware handshaking interface to handle source/destination requests for the
specific channel. Writing a ‘0’ activates the software handshaking interface to han-
dle source/destination requests.
peripheral, assign the handshaking interface to the source and destination periph-
eral. This requires programming the SRC_PER and DST_PER bits, respectively.
1024) for channel x. For example, in the register, you can program the following:
Table
40-1.
Figure 40-4 on page 1019
Table 40-1 on page
shows a Linked List example with two
1020. The
Figure 40-5 on
6430D–ATARM–25-Mar-11