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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:+ J$ [- R ~1 s) m
The firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.1 C% l7 {/ F7 }
This interface consists of four bi-directional signals and one control input. The timing and electrical
$ E+ N) w9 y- c. d n( M. [parameters of the FWH interface are similar to those of the LPC interface, to provide compatibility. c1 x% g5 }( Q+ T1 p7 Z# E
between the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as3 L# m& @/ Y/ F
well as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,, E5 m/ D( ^# L1 H4 F* E
which allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The" l; j4 t# R7 E& O2 `
Intel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code., {0 K' R. j% _3 g* \; w c! F
This ensures that all LPC devices present on the shared interface will ignore cycles destined for the3 t9 j% ?% Z/ }, a8 T2 y
FWH, without becoming confused by the different protocol.
7 P4 V; {: f# |8 I$ ^/ u Y( PFWH和LPC基本是兼容的,不过FWH比LPC多几组命令4 O" ~! V' h7 `8 B
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.
$ ]& ?2 A" D$ A6 r% S另外,可以看看这个:) i% W) @' z! B8 B
US Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
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