JAJSHI3C March 2019 – October 2019 TPS23881
PRODUCTION DATA.
COMMAND = 4Fh with 1 Data Byte, Read Only
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
ACLASS Ch4 | PCLASS Ch4 | ||||||
R-0 | R-0 | R-0 | R-0 | R-0 | R-0 | R-0 | R-0 |
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset |
Bit Descriptions: These bits represent the "assigned" and previous classification results for channel n. These bits are cleared when channel n is turned off.
Bit | Field | Type | Reset | Description | ||||||
---|---|---|---|---|---|---|---|---|---|---|
7–4 | ACLASS Ch-n | R | 0 | Assigned classification on channel n.
See Table 61 below |
||||||
3–0 | PCLASS Ch-n | R | 0 | Previous Class result on channel n.
See Table 62 below |
ACLASS-Chn | Assigned Class | |||
---|---|---|---|---|
Bit 7 | Bit 6 | Bit 5 | Bit 4 | |
0 | 0 | 0 | 0 | Unknown |
0 | 0 | 0 | 1 | Class 1 |
0 | 0 | 1 | 0 | Class 2 |
0 | 0 | 1 | 1 | Class 3 |
0 | 1 | 0 | 0 | Class 4 |
0 | 1 | 0 | 1 | Reserved |
0 | 1 | 1 | 0 | Reserved |
0 | 1 | 1 | 1 | Reserved |
1 | 0 | 0 | 0 | Class 5 - 4-Pair Single Signature |
1 | 0 | 0 | 1 | Class 6 - 4-Pair Single Signature |
1 | 0 | 1 | 0 | Class 7 - 4-Pair Single Signature |
1 | 0 | 1 | 1 | Class 8 - 4-Pair Single Signature |
1 | 1 | 0 | 0 | Reserved |
1 | 1 | 0 | 1 | Class 5 - 4-Pair Dual Signature |
1 | 1 | 1 | 0 | Reserved |
1 | 1 | 1 | 1 | Reserved |
PCLASS-Chn | Previous Class | |||
---|---|---|---|---|
Bit 7 | Bit 6 | Bit 5 | Bit 4 | |
0 | 0 | 0 | 0 | Unknown |
0 | 0 | 0 | 1 | Class 1 |
0 | 0 | 1 | 0 | Class 2 |
0 | 0 | 1 | 1 | Class 3 |
0 | 1 | 0 | 0 | Class 4 |
0 | 1 | 0 | 1 | Reserved |
0 | 1 | 1 | 0 | Class 0 |
0 | 1 | 1 | 1 | Reserved |
1 | 0 | 0 | 0 | Class 5 - 4-Pair Single Signature |
1 | 0 | 0 | 1 | Class 6 - 4-Pair Single Signature |
1 | 0 | 1 | 0 | Class 7 - 4-Pair Single Signature |
1 | 0 | 1 | 1 | Class 8 - 4-Pair Single Signature |
1 | 1 | 0 | 0 | Reserved |
1 | 1 | 0 | 1 | Class 5 - 4-Pair Dual Signature |
1 | 1 | 1 | 0 | Reserved |
1 | 1 | 1 | 1 | Reserved |
“Requested” vs. “Assigned” Classification:
The “requested” class is the classification the PSE measures during Mutual Identification prior to turn on, whereas the “assigned” class is the classification level the Channel was powered on with based on the Power Allocation setting in register 0x29h. The “requested” classification values are available in registers 0x0C-0F
For a 4-pair single signature device, both channels will report the same assigned PD classification within 5ms after classification is completed. However, only the channel that classification was measured on will have the CLSCn bit set in register 0x04h
For a 4-pair dual signature device each Channel will reports is own individually assigned PD classification within 5ms of turn on.
NOTE
Upon being powered, devices that present a class 0 signature during discovery will be given an assigned class of "Class 3"
NOTE
There is no Assigned Class assigned for ports/channels powered out of Manual/Diagnostic mode. Any settings such as the port power policing and 1x/2x foldback selection that are typically configure based on the assigned class result need to manually configured by the user.
Previous Classification
In certain circumstances the requested class result in 0x0C-0F can not properly reflect the actual classification of the PD connected to the port/channel. This will happen when a port has a power allocation limit of 15.4W and the PSE can only provide 1 classification finger during turn on. When this occurs and if the device is configured to run in Semi Auto mode with det and cls enabled, the 3-finger classification measurement that preceded the turn on detection and classification cycle will be stored here. This information can be useful in scenarios where a port had to be demoted to stay under the system power limit at turn on but additional power budget comes available later on.
NOTE
The Previous Classification results are only valid for channels being used in semi auto mode with ongoing discovery (DETE and CLE = 1).