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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:
& C, ~0 X: `. X. VThe firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.1 H | B6 c( S( t$ @4 c, l/ F g
This interface consists of four bi-directional signals and one control input. The timing and electrical
0 `8 f K, h1 Pparameters of the FWH interface are similar to those of the LPC interface, to provide compatibility
5 t' s9 E+ d8 t4 P) ^& A; X9 x- Cbetween the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as( A8 c0 b8 t: \6 s! {
well as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,
/ t( X- l( l* L; z p8 Jwhich allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The
2 T. V4 Q. G1 ? ~9 mIntel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code.
0 C% k% ~) C' tThis ensures that all LPC devices present on the shared interface will ignore cycles destined for the0 ^; @! }# B/ \8 K1 t
FWH, without becoming confused by the different protocol. _ ^: X+ E$ E) y
FWH和LPC基本是兼容的,不过FWH比LPC多几组命令8 x- p: }2 }4 H% I1 S8 H
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.' n& o7 W% u, a5 {8 y" w
另外,可以看看这个:
' o* @ J. U1 H. yUS Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
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