at91sam9263 ATMEL Corporation, at91sam9263 Datasheet - Page 287

• Manufacturer Part Number: at91sam9263
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

6249D–ATARM–20-Dec-07
4. After the DMAC selected channel has been programmed, enable the channel by writing
5. Source and destination request single and burst DMAC transactions to transfer the
6. When the block transfer has completed, the DMAC reloads the DMAC_SARx,
7. The DMA transfer proceeds as follows:
a. Write the starting source address in the DMAC_SARx register for channel x.
b. Write the starting destination address in the DMAC_DARx register for channel x.
c. Program DMAC_CTLx and DMAC_CFGx according to Row 4 as shown in
d. Write the control information for the DMA transfer in the DMAC_CTLx register for
– i. Set up the transfer type (memory or non-memory peripheral for source and
– ii. Set up the transfer characteristics, such as:
e. If gather is enabled (DMAC_CTLx.S_GATH_EN is enabled), program the
f.
g. Write the channel configuration information into the DMAC_CFGx register for chan-
– i. Designate the handshaking interface type (hardware or software) for the source
– ii. If the hardware handshaking interface is activated for the source or destination
a ‘1’ to the DMAC_ChEnReg.CH_EN bit. Make sure that bit 0 of the
DMAC_DmaCfgReg register is enabled.
block of data (assuming non-memory peripherals). The DMAC acknowledges on com-
pletion of each burst/single transaction and carry out the block transfer.
DMAC_DARx and DMAC_CTLx registers. Hardware sets the Block Complete interrupt.
The DMAC then samples the row number as shown in
DMAC is in Row 1, then the DMA transfer has completed. Hardware sets the transfer
complete interrupt and disables the channel. So you can either respond to the Block
Complete or Transfer Complete interrupts, or poll for the Channel Enable
(DMAC_ChEnReg.CH_EN) bit until it is disabled, to detect when the transfer is com-
plete. If the DMAC is not in Row 1, the next step is performed.
destination) and flow control device by programming the TT_FC of the DMAC_CTLx
register.
and destination peripherals. This is not required for memory. This step requires
programming the HS_SEL_SRC/HS_SEL_DST bits, respectively. Writing a ‘0’
activates the hardware handshaking interface to handle source/destination requests
for the specific channel. Writing a ‘1’ activates the software handshaking interface to
handle source/destination requests.
peripheral, assign handshaking interface to the source and destination peripheral.
This requires programming the SRC_PER and DEST_PER bits, respectively.
– Transfer width for the source in the SRC_TR_WIDTH field.
– Transfer width for the destination in the DST_TR_WIDTH field.
– Source master layer in the SMS field where source resides.
– Destination master layer in the DMS field where destination resides.
– Incrementing/decrementing or fixed address for source in SINC field.
– Incrementing/decrementing or fixed address for destination in DINC field.
24-2 on page
channel x. For example, in the register, you can program the following:
DMAC_SGRx register for channel x.
If scatter is enabled (DMAC_CTLx.D_SCAT_EN), program the DMAC_DSRx regis-
ter for channel x.
nel x. Ensure that the reload bits, DMAC_CFGx. RELOAD_SR and
DMAC_CFGx.RELOAD_DS are enabled.
278. Program the DMAC_LLPx register with ‘0’.
AT91SAM9263 Preliminary
Table 24-2 on page
278. If the
Table
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