阅读:2856回复:9
谁知道PDIUSBD12 Dma Bug 的详细信息
我用PDIUSBD12做了一个设备, BULK IN I/O方式工作正常, DMA方式却不工作, 据说PDIUSND12 DMA 方式有 Bug, 谁知道详细信息及解决方法, 不胜感激!!!
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沙发#
发布于:2001-08-28 10:44
真的有BUG吗?那可不得了,我正在用它做项目呢。难怪PHILIPS这么低调,说明书不详细也不更新了。
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板凳#
发布于:2001-08-28 22:20
请问你是怎样把D12的那三个脚:EOT,DMAREQ,DMACK,设置成DMA方式,
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地板#
发布于:2001-08-28 22:27
DMA 方式可能真有问题, 以下是我在 http://www.usb.org 上发现的:
I have designed a board with an USBD12 device. I've read an errata from 28 May 1998 which describes some problems with the current USBD12 version when used in DMA mode (problem named: "D12/E004:DMA bug"). I would like to know how to identify the version of D12 that I have, and if the D12 can actually work in DMA mode. ---------------------------------------------------------- I ran into this problem. I was randomly losing 1 in 65 bytes. Spent a week trying to figure what I was doing wrong. Emailed someone at Phillips who told me about the DMA bug and the timing correction for it. Seems to work fine. I was also told Rev C of the chip would meet the specs and would be shipping soon (this was a month ago). I recently inquired as to when and also how to identify, but have gotten no response. ---------------------------------------------------------- : PDIUSBD12 has a new revision which fixed the DMA problem of the critical timing of its old version. ---------------------------------------------------------- : As you may note that the last line on the chip package has a XXXXXX B -X... : The B indicates it is a second revision, : It is XXXXXX C -X now, and this means it is revision C. 我们能拿到的都是 Ver B, 怎么办, 打倒洋鬼子!!! |
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地下室#
发布于:2001-08-30 09:03
没人关注这个问题吗?
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5楼#
发布于:2001-08-30 09:21
当然关注!但就算恨得牙痒痒也没有用啊!一开始就觉得不对劲,我现在只能不用它的DMA方式了。
唉,几时才能用上中国芯、中国MCU、中国WINDOWS。。。。。。 大家有空先研究一下LINUX吧,再把台湾回归了,万一那天和老米老布或。。。翻脸了最起码还有个C3和LINUX、WINBOND、ASUS。。。 |
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6楼#
发布于:2001-08-30 14:28
[QUOTE]原本由 Truly 发表
[B] 当然关注!但就算恨得牙痒痒也没有用啊!一开始就觉得不对劲,我现在只能不用它的DMA方式了。 唉,几时才能用上中国芯、中国MCU、中国WINDOWS。。。。。。 大家有空先研究一下LINUX吧,再把台湾回归了,万一那天和老米老布或。。。翻脸了最起码还有个C3和LINUX、WINBOND、ASUS。。。 [/B][/QUOTE] 呵呵! 现在国内有公司也想做usb的芯片,不过那也要很久以后的事情了。 大概Rev B的生产了好多,老外都不要,就扔给中国人了吧?就像小日本把烂货都卖到中国一样....:( |
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7楼#
发布于:2001-08-30 16:19
谢谢几位的同情, 不过活还是要干的.
怎样才能找到errata "D12/E004DMA bug" 呢, 看来修改一下硬件时序还是能工作的. 第二条路是用I/O方式, 那就要修改设备软件, 加快 BULK 速度, 那么 Keil C 中怎样插入汇编语句呢, 我只想改一下WriteEndpoint部分. |
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8楼#
发布于:2002-05-09 23:48
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9楼#
发布于:2002-11-04 15:58
我也正在调试D12 的DMA传输方式,现在已经调试成功它的DMA read,但是在调试DMA write的时候,很不稳定。主要的问题是在配置了DMA write enable后,D12的DMREQ一直为低(在出错的时候)。
请问各位有没有遇到同样的问题?? 如何修正? |
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