Controlling passthrough of communication between multiple buses

A system comprising:

• a host device coupled to a first bus, the first bus coupled to a plurality of slave devices;
• a first slave device coupled to the host device via the first bus and including a slave state machine of a slave controller to handle receipt and transmission of information on the first bus, a first data pad coupled to the first bus, a second data pad coupled to a second bus, a first parallel input path from the first data pad to the slave controller and a second parallel input path from the first data pad to the second data pad, wherein the first input path comprises a glitch filtered path and the second input path comprises an unfiltered path;
• and
• a second slave device coupled to the first slave device via the second bus, wherein the second bus is to be disabled in absence of communications to or from the second slave device, and the slave state machine of the first slave device is to minor communication along the first bus to the second slave device via the second bus.

A method comprising:

• determining whether a passthrough command has been received within a transaction from a host to a first slave device on a first bus to which a plurality of slave devices including the first slave device are coupled;
• setting a passthrough mode indicator in a control register of the first slave device when the passthrough command has been received;
• providing a passthrough enable signal to a passthrough circuit of the first slave device responsive to the passthrough mode indicator to enable a passthrough mode;
• and
• buffering communications between the first bus and a second bus coupled between the first slave device and a second slave device in the passthrough mode, including providing the communications from an input pad of the first slave device to a state machine of the first slave device on a glitch filtered path, and providing the communications from the input pad to an output pad of the first slave device coupled to the second bus on an unfiltered path, the glitch filtered path and the unfiltered path comprising parallel paths from the input pad.