The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 19, 1998
Filed:
May. 15, 1996
Hitachi, Ltd., Tokyo, JP;
Abstract
A method and apparatus for increasing data transfer efficiency for a read operation in a non-split transaction bus environment by substituting a write operation for the read operation. The data transfer efficiency is increased and deadlocking is reduced by substituting two write operations (one from an I/O device to a bus controller and the other from the bus controller to the I/O device) for one read operation. Further, the present invention improves the efficiency of data transfer by maintaining the compatibility of a bus specification when DMA of an I/O bus having no split transfer function, such as a PCI bus or inter-I/O transfer, is executed. A processor instructs a data transfer operation to an I/O device or bus conversion adapter. The I/O device or bus conversion adapter connected to a bus outputs a write access, and a bus connection controller connected to the bus receives the write access and reads data in a main memory. The bus connection controller then transfers read data to the I/O device or the bus conversion adapter. Such an operation may also be performed between two I/O devices or bus conversion adapters.