AT90USB647-MU Atmel, AT90USB647-MU Datasheet - Page 268

• Manufacturer Part Number: AT90USB647-MU
• Description: MCU, 8BIT, 64K FLASH, USB, 64QFN
• Manufacturer: Atmel

Specifications of AT90USB647-MU

• Controller Family/series: AT90
• No. Of I/o's: 48
• Eeprom Memory Size: 2KB
• Ram Memory Size: 4KB
• Cpu Speed: 16MHz
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 64KB
• Oscillator Type: External, Internal
• Package: 64QFN EP
• Device Core: AVR
• Family Name: AT90
• Maximum Speed: 20 MHz
• Ram Size: 4 KB
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 48
• Interface Type: SPI/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 4
• Lead Free Status / Rohs Status: Details

22.4
22.5
22.6
268
USB reset
Endpoint selection
Endpoint activation
AT90USB64/128
The data toggle field remains unchanged.
The other registers remain unchanged.
The endpoint configuration remains active and the endpoint is still enabled.
The endpoint reset may be associated with a clear of the data toggle command (RSTDT bit) as
an answer to the CLEAR_FEATURE USB command.
When an USB reset is detected on the USB line, the next operations are performed by the
controller:
Prior to any operation performed by the CPU, the endpoint must first be selected. This is done
by setting the EPNUM2:0 bits (UENUM register) with the endpoint number which will be man-
aged by the CPU.
The CPU can then access to the various endpoint registers and data.
The endpoint is maintained under reset as long as the EPEN bit is not set.
The following flow must be respected in order to activate an endpoint:
• the UEINTX, UESTA0X and UESTA1X are restored to their reset value.
• all the endpoints are disabled
• the default control endpoint remains configured (see Section 22.3, page 267 for more
details).
7593K–AVR–11/09