SI3482-A01-GM Silicon Laboratories Inc, SI3482-A01-GM Datasheet - Page 15

• Manufacturer Part Number: SI3482-A01-GM
• Description: IC CTLR POE 24-48PORT PSE 24-QFN
• Manufacturer: Silicon Laboratories Inc

Specifications of SI3482-A01-GM

• Applications: Power Over Ethernet Controller
• Current - Supply: 12.1mA
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-WFQFN Exposed Pad
• Product: Power Distribution
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Si3482
The Port Information format is a sequence of fields as shown above. For more information, read the description of
the GetPortInfo() routine in the Power Manager API Section. The Routine field contains RTN_GETPORTINFO, and
the DataLength field contains 17.
The Result field contains the return code from the GetPortInfo() routine, and, if Result is not SUCCESS (0), the
remaining fields should be ignored.
The Current and PowerSupplyVoltage fields are big endian. Therefore, the most significant byte comes first.
3.1.5.4. Events Format
The Events format of the Data field is used to return events to the client. Events are returned after calling the
GetEvents() routine.
Start Routine Data Length Data Checksum
...
Event
Event
Event
Event
Type
Parm1
Parm2
Figure 12. Events Format
In the Si3482, the Serial Packet Server internally receives events from the Power Manager and stores them in a
circular event queue. If the event queue becomes full, newer events overwrite older events.
If a client wishes to receive events, it should periodically get the events from the Serial Packet Server. The client
gets the events by sending a packet with the Routine field set to RTN_GETEVENTS. The Serial Packet Server
returns all the events from the event queue in a single packet with the Data field in the Events format.
The Data field does not have a fixed length. The length of the Data field depends on the number of events that are
returned. An event is three bytes long; so, the number of events in the Data field is DataLength divided by three. If
there are no events to return, then DataLength is zero, and the Data field is empty. The maximum number of events
that can be returned is 85.
3.2. SPP Error Handling
There are many reasons why a client may not receive back a packet. Perhaps the Si3482 is not running or perhaps
the serial data was corrupted or lost during transmission (in either direction). In any case, it is not prudent for a
Serial Packet Client to call a serial receive routine that blocks forever until data is received. If the serial receive
routine does not have a timeout option, the client should not call the receive routine unless it knows that received
data is available. If a client does not receive a packet within one second of sending a packet, then the client should
assume that there has been a communications error. The client should resend the original packet or simply give up
(but do not wait forever to receive a packet).
When the Serial Packet Server receives a packet, it validates the packet. If the checksum is bad or the Routine
field is invalid, the Serial Packet Server ignores the packet and does not send back a packet in response. After one
second, the client should realize that a packet has not been received and should resend the original packet.
The Si3482 checks the configuration every 30 seconds to see if it has changed. If the configuration has changed,
the Si3482 backs up the configuration to internal flash memory. While the Si3482 is writing to flash memory, it
cannot send or receive packets on the host interface. If a host MCU sends a packet to the Si3482 while it is backing
up the configuration, the packet is lost. If a host MCU does not receive a packet back within one second, the host
MCU should resend the original packet.
Rev. 0.1
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