Abstract: An oscillator transmission switching circuit switches between asynchronous oscillator signals with low latency. Preferably, a fast switching circuit triggers a transition from a first oscillator to a second oscillator by entering a bridge input immediately following an edge of the first oscillator, holding in the bridge input until the same edge of the second oscillator is detected, and switching to the second oscillator. Preferably, the bridge input is selectable to accommodate conditions in which the first oscillator signal is stuck at either a logic 0 or a logic 1. A change of oscillators may be triggered by a fault detection circuit or by an external signal.

Abstract: Methods and apparatus are provided for connecting a manufacturing test interface to a global serial bus, such as an inter integrated circuit (I2C) bus. Input/output buffer logic buffers data to be transferred to and from the global serial bus. A slave interface logic connected to the input/output buffer logic receives and sends data to the input/output buffer logic. A slave controller coupled to the input/output buffer logic and the slave interface logic paces data exchange to the input/output buffer logic. Error detection logic is coupled between the input/output buffer and the global serial bus for detecting error conditions.