阅读:1911回复:9
关于epp1.9, 请帮忙,22分全送了
我正在作一个指纹采集器, 通过并口采集。
用普通的in, out指令速度跟不上,数据有丢失。 后来发现指纹传感器说明书上强调,必需用epp1.9才行 可是什么是epp1.9? 怎样实现? 请各位帮忙,不甚感激 |
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沙发#
发布于:2001-07-04 13:02
我也不知道,不过先得到这3分再说:D
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板凳#
发布于:2001-07-04 14:19
epp1.9是epp协议版本号,查一下IEEE的1284协议文本。
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地板#
发布于:2001-07-04 22:59
The Enhanced Parallel Port (EPP) was designed in a joint venture between Intel, Xircom & Zenith Data Systems. EPP Ports were first specified in the EPP 1.7 standard, and then later included in the IEEE 1284 Standard released in 1994. EPP has two standards, EPP 1.7 and EPP 1.9. There are differences between the two standards which may affect the operation of devices. This is further discussed latter. EPP
has a typical transfer rate in the order of 500KB/S to 2MB/S. This is achieved by allowing the hardware contained in the port to generate handshaking, strobing etc, rather that have the software do it, which was the case with Centronics. For the hobbyist, EPP is more commonly used than ECP. EPP differs from ECP by the fact that the EPP Port generates and controls all the transfers to and from the peripheral. ECP on the other hand requires the peripheral to negotiate a reverse channel and control the handshaking. This is harder to achieve with common glue logic, thus really requires a dedicated controller or ECP Peripheral Chip. 我以前下过一个并口的说明书,有兴趣可以发给你。 |
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地下室#
发布于:2001-07-05 08:03
谢谢你的回答,如果有epp1.9编程的例子请一同发过来:
lovelypengpeng@eyou.com |
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5楼#
发布于:2001-07-05 13:16
我在一家老外的网站上看到过EPP的资料,好想是德国的一家站,
其是专门讨论并口驱动的,可以找找。 |
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6楼#
发布于:2001-07-05 16:34
EPP1.7 和 EPP1。9 是两个标准 其不同:
你操作读写周期时 在EPP1。9中nWait须为低 而EPP1。7 无所谓。 可先得到5分吧? |
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7楼#
发布于:2001-07-05 17:03
谢谢,是哪个网站?
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8楼#
发布于:2002-10-19 20:06
关注~~~!
谁说有EPP 文档资料? 有人写LINUX 的PARALLEL PORT 的驱动吗? |
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9楼#
发布于:2002-11-08 13:48
http://www.beyondlogic.org/epp/epp.htm :cool:
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