37.15.3 Extended Register
| Name: | EXTREG |
| Offset: | 0x08 |
| Reset: | 0xXXXXXXX |
| Property: | N/A |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| VARIABLE[10:4] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | ||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| VARIABLE[3:0] | SUBPID[3:0] | ||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | x | 0 | 0 | 0 | x | |
Bits 14:4 – VARIABLE[10:0] Variable field send with extended token
These bits define the VARIABLE field sent with extended token. See “Section 2.1.1 Protocol Extension Token in the reference document ENGINEERING CHANGE NOTICE, USB 2.0 Link Power Management Addendum.”
To support the USB2.0 Link Power Management addition the VARIABLE field should be set as described below.
| VARIABLE | Description |
|---|---|
| VARIABLE[3:0] | bLinkState(1) |
| VARIABLE[7:4] | BESL (See LPM ECN)(2) |
| VARIABLE[8] | bRemoteWake(1) |
| VARIABLE[10:9] | Reserved |
- For a definition of LPM Token bRemoteWake and bLinkState fields, refer to "Table 2-3 in the reference document ENGINEERING CHANGE NOTICE, USB 2.0 Link Power Management Addendum".
- For a definition of LPM Token BESL field, refer to "Table 2-3 in the reference document ENGINEERING CHANGE NOTICE, USB 2.0 Link Power Management Addendum" and "Table X-X1 in Errata for ECN USB 2.0 Link Power Management.
Bits 3:0 – SUBPID[3:0] SUBPID field send with extended token
These bits define the SUBPID field sent with extended token. See “Section 2.1.1 Protocol Extension Token in the reference document ENGINEERING CHANGE NOTICE, USB 2.0 Link Power Management Addendum”.
To support the USB2.0 Link Power Management addition the SUBPID field should be set as described in “Table 2.2 SubPID Types in the reference document ENGINEERING CHANGE NOTICE, USB 2.0 Link Power Management Addendum”.