AT90USB64/128
23.16.1 General USB Host registers
Bit
7
-
6
-
5
-
4
-
3
-
2
RESUME
R/W
1
RESET
R/W
0
0
SOFEN
R/W
0
UHCON
Read/Write
Initial Value
R
0
R
0
R
0
R
0
R
0
0
• 7-3 - Reserved
The value read from these bits is always 0. Do not set these bits.
• 2 - RESUME - Send USB Resume
Set this bit to generate a USB Resume on the USB bus.
Cleared by hardware when the USB Resume has been sent. Clearing by software has no effect.
• 1 - RESET - Send USB Reset
Set this bit to generate a USB Reset on the USB bus.
Cleared by hardware when the USB Reset has been sent. Clearing by software has no effect.
Refer to the USB reset section for more details.
• 0 - SOFEN - Start Of Frame Generation Enable
Set this bit to generate SOF on the USB bus.
Clear this bit to disable the SOF generation and to leave the USB bus in Idle state.
Bit
7
-
6
HWUP
R/W
0
5
HSOF
R/W
0
4
RXRSMI
R/W
3
RSMEDI
R/W
2
RSTI
R/W
0
1
DDISCI
R/W
0
0
DCONNI
R/W
UHINT
Read/Write
Initial Value
R
0
0
0
0
• 7 - Reserved
The value read from these bits is always 0. Do not set these bits.
• 6 - HWUP
Host Wake-Up Interrupt
Set by hardware when a non-idle state is detected on the USB bus.
Shall be clear by software to acknowledge the interrupt. Setting by software has no effect.
• 5 - HSOFI - Host Start Of Frame Interrupt
Set by hardware when a SOF is issued by the Host controller. This triggers a USB interrupt
when HSOFE is set.
Shall be cleared by software to acknowledge the interrupt. Setting by software has no effect.
• 4 - RXRSMI - Upstream Resume Received Interrupt
Set by hardware when an Upstream Resume has been received from the Device.
Shall be cleared by software. Setting by software has no effect.
301
7593A–AVR–02/06
ATMEL [ ATMEL ]
