Figure 20-5. USB Device Controller Endpoint Interrupt System
Endpoint 4
Endpoint 3
Endpoint 2
Endpoint 1
Endpoint 0
OVERFI
UESTAX.6
UNDERFI
FLERRE
UESTAX.5
UEIENX.7
NAKINI
UEINTX.6
NAKINE
UEIENX.6
NAKOUTI
UEINTX.4
TXSTPE
Endpoint Interrupt
UEIENX.4
RXSTPI
EPINT
UEINTX.3
UEINT.X
TXOUTE
UEIENX.3
RXOUTI
UEINTX.2
RXOUTE
UEIENX.2
STALLEDI
UEINTX.1
STALLEDE
UEIENX.1
TXINI
UEINTX.0
TXINE
UEIENX.0
Processing interrupts are generated when:
• Ready to accept IN data(EPINTx, TXINI=1)
• Received OUT data(EPINTx, RXOUTI=1)
• Received SETUP(EPINTx, RXSTPI=1)
Exception Interrupts are generated when:
• Stalled packet(EPINTx, STALLEDI=1)
• CRC error on OUT in isochronous mode(EPINTx, STALLEDI=1)
• Overflow(EPINTx, OVERFI=1)
• Underflow in isochronous mode(EPINTx, UNDERFI=1)
• NAK IN sent(EPINTx, NAKINI=1)
• NAK OUT sent(EPINTx, NAKOUTI=1)
20.18 Registers
20.18.1 USB device general registers
Bit
7
-
6
-
5
-
4
-
3
-
2
1
0
RSTCPU
R/W
RMWKUP
R/W
DETACH
R/W
UDCON
Read/Wri
te
R
R
R
R
R
Initial
Value
0
0
0
0
0
0
0
1
208
AT90USB82/162
7707D–AVR–07/08
ATMEL [ ATMEL ]
