37.7.2 Control B Register
| Symbol | Description | Symbol | Description | Symbol | Description |
|---|---|---|---|---|---|
| R | Readable bit | HC | Cleared by Hardware | (Grey cell) | Unimplemented |
| W | Writable bit | HS | Set by Hardware | X | Bit is unknown at Reset |
| K | Write to clear | S | Software settable bit | — | — |
| Name: | CTRLB |
| Offset: | 0x0004 |
| Reset: | 0x0000000000 |
| Property: | PAC Write-Protection |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| Access | |||||||||
| Reset |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| BLANK[19:16] | |||||||||
| Access | R/W | R/W | R/W | R/W | |||||
| Reset | 0 | 0 | 0 | 0 | |||||
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| BLANK[15:8] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| BLANK[7:0] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Bits 19:0 – BLANK[19:0] Blank the Resume/Wakeup Monitoring for XCLK
Blank the Resume/Wakeup Monitoring for XCLK counts when entering Suspend When entering Suspend from HS as a Host, Blank allows time for the downstream Device to detect Suspend and switch from HS to FS (HS term to FS Pull-up) and enter its suspend state, before the Host
Resume/Wakeup monitor becomes active.
Note:
- The amount of time required to blank instability (HS term to FS pull-up) in LineState depends upon when the downstream device activates its pullup resistors in response to detecting suspend, the transmission line distance, and other factors. The user may adjust this blanking time as required but should consult the USB spec for detection of suspend/resume requirements.
- Zero is a valid value for LS or FS modes.
- This field can be safely updated when CTRLA.ENABLE=0 or when POWER.SUSPEND=.
| Value | Description |
|---|---|
| FFFFF | Maximum time to ignore Resume/Wakeup detection (220-1)*16.6ns or about 17.4ms. |
| 00010 | Ignore Resume/Wakeup detector for2*16.6ns |
| 00001 | Ignore Resume/Wakeup detector for1*16.6ns |
| 00000 | Do not ignore Resume/Wakeup detector |