| 摘要 |
<p>An asynchronous data channel carries an asynchronous signal (30) in which fields (211) of digital data, which are asynchronous within the field at a bit rate frequency, are separated by adjustment regions including a first pattern of control signals (213, 214) repeating at a first submultiple of the bit rate frequency and asecond pattern of control signals (215) repeating at a second submultiple of the bit rate frequency. First and second clock signals are derived at the two submultiple frequencies and phase coincidence between the two clock signals is detected. A synchronizing signal, produced in fixed time relationship with the coincidence detection indicates the start of the data field. The data channel can also include formatting means (41) and write circuitry for generating the appropriate control signal patterns prior to the data field and can be applied to an information storage subsystem of the moving medium type.</p> |
