AT32UC3A3128 Atmel Corporation, AT32UC3A3128 Datasheet - Page 452

• Manufacturer Part Number: AT32UC3A3128
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A3128

• Flash (kbytes): 128 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 32
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 110
• Ext Interrupts: 110
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 2
• Uart: 4
• Lin: 4
• Ssc: 1
• Sd / Emmc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 16
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 128
• Self Program Memory: YES
• External Bus Interface: 1
• Dram Memory: sdram
• 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: 18
• Input Capture Channels: 12
• Pwm Channels: 12
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Figure 22-11. Slave Receiver with Multiple Data Bytes
22.8.5
22.8.5.1
22.8.5.2
32072G–11/2011
TCOMP
RXR DY
TWD
Using the Peripheral DMA Controller
S
Data Transmit with the Peripheral DMA Controller
Data Receive with the Peripheral DMA Controller
DADR
slave to pull it down in order to generate the acknowledge. The master polls the data line during
this clock pulse.
The SR.RXRDY bit indicates that a data byte is available in the RHR. The RXRDY bit is also
used as Receive Ready for the Peripheral DMA Controller receive channel.
Figure 22-10. Slave Receiver with One Data Byte
The use of the Peripheral DMA Controller significantly reduces the CPU load. The user can set
up ring buffers for the Peripheral DMA Controller, containing data to transmit or free buffer space
to place received data. By initializing NBYTES to zero before a transfer, and writing a one to
CR.CUP, NBYTES is incremented by one each time a data has been transmitted or received.
This allows the user to detect how much data was actually transferred by the DMA system.
To assure correct behavior, respect the following programming sequences:
1. Initialize the transmit Peripheral DMA Controller (memory pointers, size, etc.).
2. Configure the TWIS (ADR, NBYTES, etc.).
3. Start the transfer by enabling the Peripheral DMA Controller to transmit.
4. Wait for the Peripheral DMA Controller end-of-transmit flag.
5. Disable the Peripheral DMA Controller.
1. Initialize the receive Peripheral DMA Controller (memory pointers, size - 1, etc.).
2. Configure the TWIS (ADR, NBYTES, etc.).
W
A
DATA n
TCOMP
RXR DY
TWD
A
S
Read RHR
DATA n
DATA (n+1)
DADR
A
DATA (n+1)
Read RHR
W
DAT A (n+m)-1
A
DATA
DAT A (n+m)-1
A
Read RHR
DATA (n+m)
Read RHR
A
P
A
DATA (n+m)
Read RHR
P
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