| 摘要 |
<p>PURPOSE:To prevent extension of the hardware even when number of VPIs is increased by setting a correspondence list among a VPI a count and a threshold level to a storage circuit and referring the correspondence list to read the content or to revise the content. CONSTITUTION:When a cell detection circuit 2 detects a valid cell and a VPI identification circuit 8 identifies a VPI, the VPI is used as an entry key to access a storage circuit 20 and to read a data coincident with the entry key. The count of the data is incremented by one, and the result and the threshold level are compared, and when the count exceeds the threshold level, a cell abort inhibit signal is sent. The count is returned to the circuit 20 and the VPI is given to the shift register 3. The register 3 is shifted for one cell time each. The circuit 20 is accessed by using the VPI obtained from each output of the register 3 as an entry key and the relevant count is decremented by one. Since the VPI is used as the entry key to access the circuit 20, the access time of the circuit 20 is reduced.</p> |
