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发表于 2008-8-21 14:36:05
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在Intel® 82802AB/82802AC Firmware Hub (FWH)的data sheet里面,有下面一段话:, s# u: J" }' I0 U: n/ \# M
The firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.8 J- i" l% M. v) S$ T$ m
This interface consists of four bi-directional signals and one control input. The timing and electrical% I9 E* Z9 j6 C! |
parameters of the FWH interface are similar to those of the LPC interface, to provide compatibility
$ a8 }# ~, R) ~/ k6 q9 Lbetween the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as& D( }! U) V1 ~ R) ~' K
well as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,
$ f8 Z: I5 i1 j3 Owhich allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The& ]9 b+ p U6 k: I3 W( {) _
Intel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code." G/ a) ?. F& \" h
This ensures that all LPC devices present on the shared interface will ignore cycles destined for the
+ f# ]7 c% \1 x3 aFWH, without becoming confused by the different protocol.% K3 x2 a' Z& m4 S9 T9 }
FWH和LPC基本是兼容的,不过FWH比LPC多几组命令8 I4 |& P9 `4 D) o
在ICH9上面LPC和FWH的数据地址控制信号线都是相同pin复用的,所以应该是二选一的吧.9 Y; G* W5 d0 w/ d7 i! C# V
另外,可以看看这个:- o; A3 H) q6 O+ G
US Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
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