AT32UC3A1256AU Atmel Corporation, AT32UC3A1256AU Datasheet - Page 514

• Manufacturer Part Number: AT32UC3A1256AU
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A1256AU

• Flash (kbytes): 256 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 32
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 69
• Ext Interrupts: 69
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 1
• Uart: 4
• Ssc: 1
• Ethernet: 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): 64
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0-3.6 or (1.65-1.95+3.0-3.6)
• Operating Voltage (vcc): 3.0-3.6 or (1.65-1.95+3.0-3.6)
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 10
• Output Compare Channels: 16
• Input Capture Channels: 6
• Pwm Channels: 13
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

32058K AVR32-01/12
30.7.2.10
30.7.2.10.1 Special Considerations for Control Endpoints
30.7.2.10.2 STALL Handshake and Retry Mechanism
30.7.2.11
30.7.2.11.1 Overview
STALL Request
Management of Control Endpoints
• The firmware may then set the RMWKUP bit to send an upstream resume to the host for a
• When the controller sends the upstream resume, the Upstream Resume interrupt (UPRSM) is
• RMWKUP is cleared by hardware at the end of the upstream resume.
• If the controller detects a valid “End of Resume” signal from the host, the End of Resume
For each endpoint, the STALL management is performed using:
To answer the next request with a STALL handshake, STALLRQ has to be set by setting the
STALLRQS bit. All following requests will be discarded (RXOUTI, etc. will not be set) and hand-
shaked with a STALL until the STALLRQ bit is cleared, what is done by hardware when a new
SETUP packet is received (for control endpoints) or when the STALLRQC bit is set.
Each time a STALL handshake is sent, the STALLEDI flag is set by the USB controller and the
EPXINT interrupt is raised.
If a SETUP packet is received into a control endpoint for which a STALL is requested, the
Received SETUP interrupt (RXSTPI) is raised and STALLRQ and STALLEDI are cleared by
hardware. The SETUP has to be ACKed.
This management simplifies the enumeration process management. If a command is not sup-
ported or contains an error, the firmware requests a STALL and can return to the main task,
waiting for the next SETUP request.
The retry mechanism has priority over the STALL handshake. A STALL handshake is sent if the
STALLRQ bit is set and if there is no retry required.
A SETUP request is always ACKed. When a new SETUP packet is received, the Received
SETUP interrupt (RXSTPI) is raised, but not the Received OUT Data interrupt (RXOUTI).
The FIFOCON and RWALL bits are irrelevant for control endpoints. The firmware shall therefore
never use them on these endpoints. When read, their value is always 0.
Control endpoints are managed using:
remote wake-up. This will automatically be done by the controller after 5 ms of inactivity on the
USB bus.
raised and SUSP is cleared by hardware.
interrupt (EORSM) is raised.
•the STALL Request bit (STALLRQ) to initiate a STALL request;
•the STALLed interrupt (STALLEDI) raised when a STALL handshake has been sent.
•the Received SETUP interrupt (RXSTPI) which is raised when a new SETUP packet is
received and which shall be cleared by firmware to acknowledge the packet and to free the
bank;
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