Register Map
13-24
13.2.7.5
External Pullup Enable (Pullup_En)
Allows the device to disconnect itself from the USB bus, forcing the host to
reset and reconfigure the device. This bit can be used to prevent USB traffic
when the device is not ready.
0: Pullup disabled. USB host cannot detect the device. In this mode, the
48-MHz USB clock is forced off.
1: Pullup enabled.
Value after local host reset is low, after USB reset is high, after detach is
unchanged.
13.2.8 System Configuration Register 2 (SYSCON2)
The set-only system configuration 2 register (SYSCON2) provides miscella-
neous controls for the function. A read of this register always returns 0.
Table 13–9. SYSCON2 – System Configuration Register 2 (SYSCON2)
Bit
Name
Description
15–7
–
Reserved
6
Rmt_Wkp
Remote wakeup
5
Stall_Cmd
Stall command
4
–
Reserved
3
Dev_Cfg
Device configured
2
Clr_Cfg
Clear configured
1–0
–
Reserved
13.2.8.1
Remote Wakeup (Rmt_Wkp)
This set-only bit when written with a 1 initiates the remote wakeup sequence,
regardless of whether or not the R_Wk_OK bit has been previously set to 1 by
the USB host. So the MPU must make sure that remote wakeup has been
enabled by the USB host by reading the DEVSTAT register to check that the
R_Wk_OK bit [6] is set to 1 before generating a remote wakeup by writing a
1 to the Rmt_Wkp bit [6]. Reading the Rmt_Wkp bit always returns 0. Writing
0 into this bit has no effect.
0: No action
1: Initiates the remote wakeup sequence
Always read 0.