| 摘要 |
<p>PURPOSE:To improve the use efficiency of a shared serial bus by controlling the use allocation of the shared serial bus existing in a digital communication equipment. CONSTITUTION:It is assumed that a control package 10 transmits a request signal in the middle of pulses 1 and 2 as against frame pulses 1-6 by a common clock. Since there is no request signal from others, a mediation circuit 31 returns a permission signal to the package 10. Consequently, data is outputted from a serial data transmission circuit 12 to the shared serial bus. When the package 10 terminates the output of data and release the request signal by the pulse 4, the permission signal is released. Even if a package 20 transmits the request signal in the middle of the frame pulses 2 and 3, the package 20 comes to a use permission waiting state until the permission signal for the package 10 is released by the pulse 4. When the permission signal of the package 10 is released by the pulse 4, a mediation package 30 gives the permission signal to the package 20 and connects the shared bus to the package 20. When the request signal of the package 20 is released, the output of the permission signal and output data is stopped.</p> |
