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. In this mode, the Intel^® Management Engine (Intel^® CSME) SMBus controllers are not used and should be disabled by soft strap.

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.

Advanced TCO Mode

The PCH supports the Advanced TCO mode in which SMLink0 and SMLink1 are used in addition to the host SMBus.

In this mode, the Intel^® CSME SMBus controllers must be enabled by soft strap in the flash descriptor. Refer to the figure below for more details.

In advanced TCO mode, the TCO slave can either be connected to the host SMBus or the SMLink0.

SMLink0 is targeted for integrated LAN and NFC use. When an Intel LAN PHY is connected to SMLink0, a soft strap must be set to indicate that the PHY is connected to SMLink0. When the Fast Mode is enabled using a soft strap, the interface will be running at the frequency of up to 1 MHz depending on different factors such as board routing or bus loading.

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.