| 摘要 |
<p>A communication control unit is provided which is capable of retrieving a path regardless of a length of an address to be retrieved, of reducing a scale of its circuit, of achieving a high speed processing of retrieval and of preventing an increase in memory size required. The communication control unit is composed of a retrieval data managing circuit adapted to represent a node of a path tree corresponding to a path table by a split address obtained by setting-off a real address by one byte and a split mask length and to produce an address comparison byte composed of four stages obtained by setting-off a retrieving address by one byte and a next node selection byte, a nex-node selecting circuit adapted to decide a node to be retrieved next based oil the next node selection byte and a path retrieving circuit adapted to compare valid address portion showing a split mask length out of the split address with a split mask length portion of the address comparison byte.</p> |
