Register Map
13-26
13.2.9 Device Status Register (DEVSTAT)
The read-only device status register (DEVSTAT) provides a status reflecting
the visible device states as defined in USB1.1 chapter 9. A write to this register
has no effect.
This register is double buffered. If the DS_Chg_IE bit is set (interrupt enabled),
the background register is moved to foreground position only after clearing any
pending DS_Chg interrupts. So if there is a state change and there is still a
pending DS_Chg interrupt, then recent state change is not visible because the
background register was updated and not moved into foreground position.
Table 13–10. Device Status Register (DEVSTAT)
Bit
Name
Description
15–7
–
Reserved
6
R_WK_OK
Remote wakeup granted
5
USB_Reset
USB reset signaling is active
4
SUS
Suspended state
3
CFG
Configured state
2
ADD
Addressed state
1
DEF
Default state
0
ATT
Attached state
13.2.9.1
Remote Wakeup Enabled (R_WK_OK)
This bit is automatically set and cleared when the core receives a valid set/
clear device feature request from the USB host. It returns a 1 when the USB
host has granted the function the ability to assert remote wakeup.
0: Not significant
1: Remote wakeup granted
Value after local host or USB reset is low.