Invention Grant
US08417842B2 Virtual direct memory access (DMA) channel technique with multiple engines for DMA controller
有权
用于DMA控制器的多引擎的虚拟直接存储器访问(DMA)通道技术
- Patent Title: Virtual direct memory access (DMA) channel technique with multiple engines for DMA controller
- Patent Title (中): 用于DMA控制器的多引擎的虚拟直接存储器访问(DMA)通道技术
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Application No.: US12122340Application Date: 2008-05-16
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Publication No.: US08417842B2Publication Date: 2013-04-09
- Inventor: Mieu Vu
- Applicant: Mieu Vu
- Applicant Address: US TX Austin
- Assignee: Freescale Semiconductor Inc.
- Current Assignee: Freescale Semiconductor Inc.
- Current Assignee Address: US TX Austin
- Agency: Zagorin O'Brien Graham LLP
- Main IPC: G06F13/28
- IPC: G06F13/28

Abstract:
A virtual DMA channel technique in which a generally larger number of DMA channels are mapped to a generally smaller number of DMA engines can provide a configuration in which switches amongst DMA engines (and therefore amongst a current working set of DMA channels currently mapped thereto) can be accomplished without context switch latency. Accordingly, as long as contents of the current working set can be appropriately managed, many changes (whether or nor priority based) between a current active DMA channel and a next runnable DMA channel can be accomplished without incurring a context switch latency such as normally associated with loading/restoring and/or saving DMA context information. In some embodiments, a working set or replacement strategy that seeks to cache a most frequently (or most recently) used subset of virtual DMA channels is employed. In some embodiments, a set- or frame-oriented variants of such strategies may be employed.
Public/Granted literature
- US20090287857A1 Virtual Memory Direct Access (DMA) Channel Technique with Multiple Engines for DMA Controller Public/Granted day:2009-11-19
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