Intel® 500 Series Chipset Family On-Package PCH Datasheet Volume 1
Datasheet
TCO Modes
TCO Compatible Mode
In TCO Legacy/Compatible mode, only the host SMBus is used. The TCO Slave is connected to the host SMBus internally by default.
TCO Compatible Mode SMBus Configuration
In TCO Legacy/Compatible mode the PCH can function directly with an external LAN controller or equivalent external LAN controller to report messages to a network management console without the aid of the system processor. This is crucial in cases where the processor is malfunctioning or cannot function due to being in a low-power state. The table below includes a list of events that will report messages to the network management console.
| Event | Assertion? | Deassertion? | Comments |
|---|---|---|---|
| INTRUDER# pin | Yes | No | System must hang in S0 state |
| TCO Watchdog Timer Expired | Yes | N/A | System will enter to hang state |
| SMBALERT# pin | Yes | Yes | System must hang in S0 state |
| BATLOW# | Yes | Yes | System must hang in S0 state |
Advanced TCO Mode
The PCH supports the Advanced TCO mode in which SMLink0 and SMLink1 are used in addition to the host SMBus.
In advanced TCO mode, the TCO slave can either be connected to the host SMBus or the SMLink0.
SMLink0 is targeted for integrated LAN.
SMLink1 can be connected to an Embedded Controller (EC) or Baseboard Management Controller (BMC) use. In the case where a BMC is connected to SMLink1, the BMC communicates with the Intel Management Engine through the Intel® CSME SMBus connected to SMLink1. The host and TCO slave communicate with BMC through SMBus.