ATMEGA8U2-MU Atmel, ATMEGA8U2-MU Datasheet - Page 220

• Manufacturer Part Number: ATMEGA8U2-MU
• Description: MCU AVR 8K FLASH USB 32-VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8U2-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Processor Series: ATMEGA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: SPI, UART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, AT90USBKEY, ATEVK525
• Minimum Operating Temperature: - 40 C
• Package: 32QFN EP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 16 MHz
• Operating Supply Voltage: 3.3|5 V
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

21.18.16 UEIENX – USB Endpoint Interrupt Enable Register
7799D–AVR–11/10
This flag is set by the USB controller when the current bank contains a new packet. This
RXOUTI flag can generate a “USB endpoint interrupt” if RXOUTE bit is set. Writing this bit to
zero acknowledges the interrupt source (USB clocks must be enabled before). Writing this bit to
one has no effect for an OUT endpoint.
Writing this bit to one kills the last loaded bank. This sequence can be used to cancelled a previ-
ously loaded endpoint. Clearing by software has no effect. See
Abort.
• Bit 1 – STALLEDI: STALLEDI Interrupt Flag
This flag is set by the USB controller when STALL handshake has been sent, or when a CRC
error has been detected for an isochronous OUT endpoint. This STALLEDI flag can generate a
“USB endpoint interrupt” if STALLEDE bit is set. Writing this bit to zero acknowledges the inter-
rupt source (USB clocks must be enabled before). Writing this bit to one has no effect.
• Bit 0 – TXINI: Transmitter Ready Interrupt Flag
This flag is set by the USB controller when the current bank is free and can be filled. This TXINI
flag can generate a “USB endpoint interrupt” if TXINE bit is set. Writing this bit to zero acknowl-
edges the interrupt source (USB clocks must be enabled before). Writing this bit to one has no
effect.
• Bit 7 – FLERRE: Flow Error Interrupt Enable Flag
Writing this bit to one enables interrupt on OVERFI or UNDERFI flags. An overflow or underflow
interrupt will be generated only if the FLERRE bit is set to one, the Global Interrupt Flag in SREG
is written to one, and the OVERFI or UNDERFI flags are set.
• Bit 6 – NAKINE: NAK IN Interrupt Enable Bit
Writing this bit to one enables interrupt on NAKINI flag. A NAK IN interrupt will be generated only
if the NAKINE bit is set to one, the Global Interrupt Flag in SREG is written to one, and the
NAKINI is set.
• Bit 5 – Res: Reserved
This bit is reserved and will always read as zero.
• Bit 4 – NAKOUTE: NAK OUT Interrupt Enable Bit
Writing this bit to one enables interrupt on NAKOUTI flag. A NAKOUT interrupt will be generated
only if the NAKOUTE bit is set to one, the Global Interrupt Flag in SREG is written to one, and
the NAKOUTI is set.
Bit
(0xF0)
Read/Write
Initial Value
• Endpoint IN direction (KILLBK bit)
FLERRE
R/W
7
0
NAKINE
R/W
6
0
R
5
0
-
NAKOUTE
R/W
4
0
RXSTPE
ATmega8U2/16U2/32U2
R/W
3
0
RXOUTE
R/W
2
0
page 206
STALLEDE
R/W
1
0
for more details on the
TXINE
R/W
0
0
UEIENX
220