Communication control device and method

A communication control device includes a determination circuit for determining whether reception of an asynchronous packet from an IEEE 1394 serial bus is allowed or denied by comparing the sum of the size of the asynchronous packet to be received and the size of packets currently stored in a receive FIFO unit with the size of packets which can be stored in the receive FIFO unit. The communication control device further includes an acknowledge generating circuit for generating an acknowledge signal asserting whether reception of the asynchronous packet is allowed or denied based on the determination result of the determination circuit, and the generated acknowledge signal is sent back to the IEEE 1394 serial bus.