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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:
& R4 c( l! V$ d$ E/ QThe firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.
% g( F% W) E7 U0 |4 y; R1 gThis interface consists of four bi-directional signals and one control input. The timing and electrical
3 y$ F7 g8 r& e. S' Eparameters of the FWH interface are similar to those of the LPC interface, to provide compatibility& \: }+ {6 V+ e J. O
between the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as
2 X- E$ X, q7 Gwell as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,
- G/ p9 M1 S. {6 l: B& `! i S! Gwhich allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The
, q b4 t L4 U! t! \Intel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code.' p! X) D) ]* ~1 g6 n
This ensures that all LPC devices present on the shared interface will ignore cycles destined for the, i% `8 G1 [4 `. p% h, w
FWH, without becoming confused by the different protocol.2 H% [% }" A/ p5 }7 T' |! \7 V
FWH和LPC基本是兼容的,不过FWH比LPC多几组命令8 o, e1 ^+ w& j& g4 c) E& s
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.8 v0 ?( _) K) i1 @4 l
另外,可以看看这个:* [- D* K5 _2 _1 R0 \
US Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
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