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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:$ ]6 g; E1 ^0 \
The firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world." g1 u( t, g% F5 A) J) J ]1 k6 D1 a0 s
This interface consists of four bi-directional signals and one control input. The timing and electrical
I! T O9 f* R1 R7 eparameters of the FWH interface are similar to those of the LPC interface, to provide compatibility
3 b* }0 a+ H. e, X8 G& fbetween the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as
: \" v0 C2 `4 p( H5 twell as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,
. b* l* T K$ W7 H3 Q+ y; ?9 @+ c/ qwhich allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The, Y5 {0 B2 j7 {
Intel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code.
1 c0 O# w0 ~- E6 KThis ensures that all LPC devices present on the shared interface will ignore cycles destined for the
: F/ o2 P. q/ x6 p, d* a& L! zFWH, without becoming confused by the different protocol.5 ]9 x1 P6 R) r& a
FWH和LPC基本是兼容的,不过FWH比LPC多几组命令
3 G# r) `1 T. o* P ?6 v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.- p. Q4 F; D! _$ y/ w0 S; }" T
另外,可以看看这个:, Z6 {0 [# u7 x9 y" r
US Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
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