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. 08, 2012
Filed:
Mar. 21, 2008
Yasushi Nagai, Fujisawa, JP;
Hiroshi Nakagoe, Yokohama, JP;
Shigeki Taira, Yokohama, JP;
Renesas Electronics Corporation, Kanagawa, JP;
Abstract
A DMA controller achieving real-time control of a DMA transfer relating to periodically operated peripheral devices at a low cost and with low power consumption. A typical embodiment of the invention is a DMA controller having: a counter for counting time; a counter comparator comparing a value of the counter and a counter value indicating an expected time of a DMA transfer; a peripheral device read unit reading a register of the peripheral device to acquire a state of a peripheral device by; and a state comparator comparing a value of the register read by the peripheral device read unit and a start condition of the DMA transfer, in which, with being triggered by establishment of a comparison result by the counter comparator, in accordance with a specified order, a processing of updating the counter value indicating the expected time of a DMA transfer to a value indicating a next expected time, a read of the register of the peripheral device by the peripheral device read unit, a comparison by the state comparator, and a DMA transfer on the condition that the comparison result by the state comparator is established are executed.