Data transfer control device and electronic equipment

• US 20050044291A1
• Filed: 10/12/2004
• Published: 02/24/2005
• Est. Priority Date: 10/15/1999
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Sato, Daisuke, Horiuchi, Hiroshi
• Granted Patent: US 7,249,204 B2
• Time in Patent Office: Days
• US Class Current: 710/33
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/36 by determining packet size, e.g. maximum transfer unit [MTU]

Abstract

A data transfer control device and electronic equipment that make it possible to implement high-speed data transfer while observing restriction that prevent the traversing of page boundaries. A data transfer control device that conforms to the IEEE 1394 standard comprises a page table fetch circuit for fetching a page table from another node if a page table exists in a data buffer at the initiator, a page table creation circuit for creating a virtual page table if no page table exists, and an SBP-2 core for automatically dividing transfer data into a series of packets that do not traverse page boundaries based on the thus fetched or created page table and transmitting them. The page table creation circuit creates a page table in which a portion between a start address and a Kth page boundary is an X-type page table element, a portion between the Kth and Lth page boundaries is a Y-type page table element, and a portion between the Lth page boundary and an end address is a Z-type page table element.

Claims

1. A data transfer control device for transferring data among a plurality of nodes that are connected to a bus, the data transfer control device comprising:

a page table fetch circuit that operates when a page table exists in a storage means of another node, to fetch the page table from the other node;

a page table creation circuit that operates when no page table exists in a storage means of the other node, to create a virtual page table based on page boundary information; and

a transfer execution circuit which executes processing to divide transfer data into packets that do not traverse page boundaries, based on the thus fetched or created page table, and transmit the packets.