注册 登录  
 加关注
   显示下一条  |  关闭
温馨提示!由于新浪微博认证机制调整,您的新浪微博帐号绑定已过期,请重新绑定!立即重新绑定新浪微博》  |  关闭

dp: 生活的脚步,进步的点滴...

Cam、DSP、FPGA、PM、Life、More ...

 
 
 

日志

 
 

IPC、Packet DMA、EDMA3  

2012-07-27 09:52:09|  分类: 专业 |  标签: |举报 |字号 订阅

  下载LOFTER 我的照片书  |
IPC (InterProcessor Communication) is a rather overused term. In general, it refers to synchronization/messaging between processors or even tasks. On Keystone devices (and earlier TI processors) there are also “IPC” registers, which provide a rudimentary core-to-core interrupt capability.

EDMA3 is a normal (though very flexible) DMA, which can be used for simple messaging schemes by using its Transfer Completion interrupts. So in this respect, EDMA3 can be used as an IPC module.

Multicore Navigator is a combination of a hardware Queue Manager Subsystem (a Queue Manager plus several dedicated firmware processors and other auxiliary pieces) plus a number of pktDMAs (Packet DMA) that are distributed around the device. The number of pktDMAs varies from device to device, but in Appleton (TCI6614) there are pktDMAs in these IP:
AIF
BCP
FFTC (x2)
NetCP
QMSS (infrastructure – a memory to memory pktDMA)
SRIO

There are several ways that Navigator can be used as an IPC module:
Synchronization:
- Queues can be polled, by multiple “slaves” if necessary.
- Special queues can trigger CP-INTC interrupts.
- QMSS INTD can be used independently to trigger interrupts.
Messaging:
- QM by itself can be used for zero-copy or shared memory messages.
- QM with Infrastructure pktDMA for point-to-point messages. Rx queues can be polled or interrupt driven.
- QM with Infrastructure pktDMA and Accumulator. Accumulator firmware performs Rx queue management in the background with interrupts to host.

So it is much more flexible than the IPC registers and EDMA3 combined.

Differences between EDMA3 and pktDMA:
EDMA3 is slightly faster.
pktDMA is more flexible.
pktDMA is unconcerned with data format or stride. It simply moves chunks of data.
pktDMA (and QM) handle atomicity issues.
pktDMA is easier to program and use, though it requires more initial setup than EDMA3.
There is a wider variety of ways to respond to pktDMA outputs (descriptors written to Rx queues).

pktDMA transfers can be chained from one to another.


Reference:

http://focus.ti.com/docs/training/catalog/events/event.jhtml?sku=OLT110027

  评论这张
 
阅读(798)| 评论(0)
推荐

历史上的今天

在LOFTER的更多文章

评论

<#--最新日志,群博日志--> <#--推荐日志--> <#--引用记录--> <#--博主推荐--> <#--随机阅读--> <#--首页推荐--> <#--历史上的今天--> <#--被推荐日志--> <#--上一篇,下一篇--> <#-- 热度 --> <#-- 网易新闻广告 --> <#--右边模块结构--> <#--评论模块结构--> <#--引用模块结构--> <#--博主发起的投票-->
 
 
 
 
 
 
 
 
 
 
 
 
 
 

页脚

网易公司版权所有 ©1997-2016