AT32UC3A4128 Atmel Corporation, AT32UC3A4128 Datasheet - Page 324

• Manufacturer Part Number: AT32UC3A4128
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A4128

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• Hardware Qtouch Acquisition: No
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 2
• Uart: 4
• Sd / Emmc: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 128
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0 to 3.6
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

19.8.2.1
Figure 19-6. External DMA Request Timing
19.9
32072G–11/2011
nDMAREQx
DMACA Transfer Types
dma_ack
dma_req
Hclk
External DMA Request Definition
When an external slave peripheral requires the DMACA to perform DMA transactions, it commu-
nicates its request by asserting the external nDMAREQx signal. This signal is resynchronized to
ensure a proper functionality (see
The external nDMAREQx signal should be asserted when the source threshold level is reached.
After resynchronization, the rising edge of dma_req starts the transfer. An external DMAACKx
acknowledge signal is also provided to indicate when the DMA transfer has completed. The
peripheral should de-assert the DMA request signal when DMAACKx is asserted.
The external nDMAREQx signal must be de-asserted after the last transfer and re-asserted
again before a new transaction starts.
For a source FIFO, an active edge should be triggered on nDMAREQx when the source FIFO
exceeds a watermark level. For a destination FIFO, an active edge should be triggered on
nDMAREQx when the destination FIFO drops below the watermark level.
The source transaction length, CTLx.SRC_MSIZE, and destination transaction length,
CTLx.DEST_MSIZE, must be set according to watermark levels on the source/destination
peripherals.
A DMA transfer may consist of single or multi-block transfers. On successive blocks of a multi-
block transfer, the SARx/DARx register in the DMACA is reprogrammed using either of the fol-
lowing methods:
On successive blocks of a multi-block transfer, the CTLx register in the DMACA is re-pro-
grammed using either of the following methods:
When block chaining, using linked lists is the multi-block method of choice, and on successive
blocks, the LLPx register in the DMACA is re-programmed using the following method:
• Block chaining using linked lists
• Auto-reloading
• Contiguous address between blocks
• Block chaining using linked lists
• Auto-reloading
• Block chaining using linked lists
DMA Transfers
DMA Transaction
DMA Transfers
”External DMA Request Timing” on page
DMA Transfers
324).
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