ATxmega256A3BU USB registers The 15 registers of USB (USB), from 0x4C0, with their reset value and every field. The ATxmega256A3BU has 695 registers in 66 peripherals, one page each.
USB USB CTRLAControl Register A
Address 0x4C0
Reset 0x00
Access read/write 7 ENABLE 6 SPEED 5 FIFOEN 4 STFRNUM 3 MAXEP3 2 MAXEP2 1 MAXEP1 0 MAXEP0 5 fields
Field Bits What it does ENABLE 7 USB Enable SPEED 6 Speed Select FIFOEN 5 USB FIFO Enable STFRNUM 4 Store Frame Number Enable MAXEP 3:0 Maximum Endpoint Addresses
CTRLBControl Register B
Address 0x4C1
Reset 0x00
Access read/write 7 – 6 – 5 – 4 PULLRST 3 – 2 RWAKEUP 1 GNACK 0 ATTACH 4 fields
Field Bits What it does PULLRST 4 Pull during Reset RWAKEUP 2 Remote Wake-up GNACK 1 Global NACK ATTACH 0 Attach
STATUSStatus Register
Address 0x4C2
Reset 0x00
Access read/write 7 – 6 – 5 – 4 – 3 URESUME 2 RESUME 1 SUSPEND 0 BUSRST 4 fields
Field Bits What it does URESUME 3 Upstream Resume RESUME 2 Resume SUSPEND 1 Bus Suspended BUSRST 0 Bus Reset
ADDRAddress Register
Address 0x4C3
Reset 0x00
Access read/write 7 – 6 ADDR6 5 ADDR5 4 ADDR4 3 ADDR3 2 ADDR2 1 ADDR1 0 ADDR0 1 field
Field Bits What it does ADDR 6:0 Device Address
FIFOWPFIFO Write Pointer Register
Address 0x4C4
Reset 0x00
Access read/write 7 – 6 – 5 – 4 FIFOWP4 3 FIFOWP3 2 FIFOWP2 1 FIFOWP1 0 FIFOWP0 1 field
Field Bits What it does FIFOWP 4:0 FIFO Write Pointer
FIFORPFIFO Read Pointer Register
Address 0x4C5
Reset 0x00
Access read/write 7 – 6 – 5 – 4 FIFORP4 3 FIFORP3 2 FIFORP2 1 FIFORP1 0 FIFORP0 1 field
Field Bits What it does FIFORP 4:0 FIFO Read Pointer
EPPTREndpoint Configuration Table Pointer
Address 0x4C6
Reset 0x0000
Access read/write
Size 16-bit INTCTRLAInterrupt Control Register A
Address 0x4C8
Reset 0x00
Access read/write 7 SOFIE 6 BUSEVIE 5 BUSERRIE 4 STALLIE 3 – 2 – 1 INTLVL1 0 INTLVL0 5 fields
Field Bits What it does SOFIE 7 Start Of Frame Interrupt Enable BUSEVIE 6 Bus Event Interrupt Enable BUSERRIE 5 Bus Error Interrupt Enable STALLIE 4 STALL Interrupt Enable INTLVL 1:0 Interrupt Level0 Interrupt disabled1 Low level2 Medium level3 High level
INTCTRLBInterrupt Control Register B
Address 0x4C9
Reset 0x00
Access read/write 7 – 6 – 5 – 4 – 3 – 2 – 1 TRNIE 0 SETUPIE 2 fields
Field Bits What it does TRNIE 1 Transaction Complete Interrupt Enable SETUPIE 0 SETUP Transaction Complete Interrupt Enable
INTFLAGSACLRClear Interrupt Flag Register A
Address 0x4CA
Reset 0x00
Access read/write 7 SOFIF 6 SUSPENDIF 5 RESUMEIF 4 RSTIF 3 CRCIF 2 UNFIF 1 OVFIF 0 STALLIF 8 fields
Field Bits What it does SOFIF 7 Start Of Frame Interrupt Flag SUSPENDIF 6 Suspend Interrupt Flag RESUMEIF 5 Resume Interrupt Flag RSTIF 4 Reset Interrupt Flag CRCIF 3 Isochronous CRC Error Interrupt Flag UNFIF 2 Underflow Interrupt Flag OVFIF 1 Overflow Interrupt Flag STALLIF 0 STALL Interrupt Flag
INTFLAGSASETSet Interrupt Flag Register A
Address 0x4CB
Reset 0x00
Access read/write 7 SOFIF 6 SUSPENDIF 5 RESUMEIF 4 RSTIF 3 CRCIF 2 UNFIF 1 OVFIF 0 STALLIF 8 fields
Field Bits What it does SOFIF 7 Start Of Frame Interrupt Flag SUSPENDIF 6 Suspend Interrupt Flag RESUMEIF 5 Resume Interrupt Flag RSTIF 4 Reset Interrupt Flag CRCIF 3 Isochronous CRC Error Interrupt Flag UNFIF 2 Underflow Interrupt Flag OVFIF 1 Overflow Interrupt Flag STALLIF 0 STALL Interrupt Flag
INTFLAGSBCLRClear Interrupt Flag Register B
Address 0x4CC
Reset 0x00
Access read/write 7 – 6 – 5 – 4 – 3 – 2 – 1 TRNIF 0 SETUPIF 2 fields
Field Bits What it does TRNIF 1 Transaction Complete Interrupt Flag SETUPIF 0 SETUP Transaction Complete Interrupt Flag
INTFLAGSBSETSet Interrupt Flag Register B
Address 0x4CD
Reset 0x00
Access read/write 7 – 6 – 5 – 4 – 3 – 2 – 1 TRNIF 0 SETUPIF 2 fields
Field Bits What it does TRNIF 1 Transaction Complete Interrupt Flag SETUPIF 0 SETUP Transaction Complete Interrupt Flag
CAL0Calibration Byte 0
Address 0x4FA
Reset 0x00
Access read/write 7 – 6 – 5 – 4 – 3 – 2 – 1 – 0 – CAL1Calibration Byte 1
Address 0x4FB
Reset 0x00
Access read/write 7 – 6 – 5 – 4 – 3 – 2 – 1 – 0 – 
BETA