Asynchronous and/or synchronous zero charge telephony protocol systems and methods may include an asynchronous signaling switch and/or a call duration time quota from a synchronous charging onset to place and complete a call. A call request is received with a second device mobile address. The asynchronous systems include instructions to automatically modify the mobile address with a routing prefix when the first device has insufficient balance or independent of balance, route to the asynchronous signaling switch based on an associated modified address trunk path, revert to the call signal at the asynchronous signaling switch, and deliver and automatically disconnect the call immediately when the call is completed. The synchronous systems include instructions to automatically set the call duration time quota upon insufficient balance, and deliver and automatically disconnect the call from the second user mobile device when the call is completed and the call duration time quota is exceeded.

Asynchronous and/or synchronous zero charge telephony protocol systems and methods may include an asynchronous signaling switch and/or a call duration time quota from a synchronous charging onset to place and complete a call. A call request is received with a second device mobile address. The asynchronous systems include instructions to automatically modify the mobile address with a routing prefix when the first device has insufficient balance or independent of balance, route to the asynchronous signaling switch based on an associated modified address trunk path, revert to the call signal at the asynchronous signaling switch, and deliver and automatically disconnect the call immediately when the call is completed. The synchronous systems include instructions to automatically set the call duration time quota upon insufficient balance, and deliver and automatically disconnect the call from the second user mobile device when the call is completed and the call duration time quota is exceeded.

Asynchronous and/or synchronous zero charge telephony protocol systems and methods may include an asynchronous signaling switch and/or a call duration time quota from a synchronous charging onset to place and complete a call. A call request is received with a second device mobile address. The asynchronous systems include instructions to automatically modify the mobile address with a routing prefix when the first device has insufficient balance or independent of balance, route to the asynchronous signaling switch based on an associated modified address trunk path, revert to the call signal at the asynchronous signaling switch, and deliver and automatically disconnect the call immediately when the call is completed. The synchronous systems include instructions to automatically set the call duration time quota upon insufficient balance, and deliver and automatically disconnect the call from the second user mobile device when the call is completed and the call duration time quota is exceeded.

Asynchronous and/or synchronous zero charge telephony protocol systems and methods may include an asynchronous signaling switch and/or a call duration time quota from a synchronous charging onset to place and complete a call. A call request is received with a second device mobile address. The asynchronous systems include instructions to automatically modify the mobile address with a routing prefix when the first device has insufficient balance or independent of balance, route to the asynchronous signaling switch based on an associated modified address trunk path, revert to the call signal at the asynchronous signaling switch, and deliver and automatically disconnect the call immediately when the call is completed. The synchronous systems include instructions to automatically set the call duration time quota upon insufficient balance, and deliver and automatically disconnect the call from the second user mobile device when the call is completed and the call duration time quota is exceeded.

Various example embodiments herein provide methods, circuits, and systems, for controlling a multicycle path in a serializer interface. The method includes determining a desired delay window of a multicycle data path in a serializer interface by sampling at least one step response from serializer delay replica circuitry at an edge of a first clock signal and a gating signal, in response to synchronizing a second clock signal with a negative edge of the first clock signal, configuring a polarity of a latch in a subsequent serializer of a serializer chain based on the determined desired delay window, and controlling the multicycle data path in the serializer interface based on the configured polarity of the latch in the subsequent serializer of the serializer chain.