KSZ8863FLLI

The KSZ8863MLL/FLL/RLL switches offer a bypass mode for system-level power saving, where the switch function between Port1 and Port2 is sustained, and packets with DA to port 3 will be dropped to make buffer memory more efficient for data transfer

The three different variants of the KSZ8863 family mentioned in the datasheet are: 1. KSZ8863 MLL: Two 10/100BASE-T/TX transceivers and one MII interface. 2. KSZ8863 RLL: Two 10/100BASE-T/TX transceivers and one RMII interface. 3. KSZ8863FLL: One 100BASE-FX, one 10/100BASE-T/TX transceivers, and one MII interface. The datasheet and supporting documents for these variants can be found on Micrel's website at www.micrel.com.

The KSZ8863MLL/FLL/RLL switches can operate in the energy detect mode to save power. This mode allows the device to save up to 87% of power when not connected to an active link partner. Additionally, the switches can automatically switch to a low power state in the energy detect mode if the cable is not plugged in. The energy detect mode consists of two states: normal power state and low power state, with the low power state reducing power consumption by disabling all circuitry except the energy detect circuitry of the receiver. The switches can also operate in the bypass mode, which enables system-level power saving when the CPU enters a power-saving mode, allowing the switch function between Port1 and Port2 to be sustained without using internal buffer memory. The power saving is more efficient in the energy detect mode with the bypass mode being used. The switches can transition between different power management operation modes during normal operation mode by setting specific bits in a register. The switches can automatically power up to the normal power state from the low power state in the energy detect mode when activity resumes due to plugging a cable or attempting to establish a link. Therefore, the KSZ8863MLL/FLL/RLL switches can operate in the energy detect mode and bypass mode to save power as described in the datasheet.