|
|
发表于 2008-8-21 14:36:05
|
显示全部楼层
在Intel® 82802AB/82802AC Firmware Hub (FWH)的data sheet里面,有下面一段话:* n6 D4 E/ ]7 Z% U$ a& @0 L+ I
The firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.
5 _ X5 ?$ j$ w5 t D/ t' ?This interface consists of four bi-directional signals and one control input. The timing and electrical
9 h0 ?9 I# E7 W6 yparameters of the FWH interface are similar to those of the LPC interface, to provide compatibility
0 {0 V: b- h3 r6 q. G+ Gbetween the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as6 n: H! m+ ^+ u4 @) L
well as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,
$ O, K! j# H. K( \' Qwhich allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The1 R5 w. N+ s( X1 V8 W& O
Intel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code.- e' h/ }; C7 d' I# d8 |
This ensures that all LPC devices present on the shared interface will ignore cycles destined for the
1 Q6 Y! l3 U7 W: M" B: H, HFWH, without becoming confused by the different protocol.
' _# p+ E! M0 V6 Q' v* n- B3 SFWH和LPC基本是兼容的,不过FWH比LPC多几组命令( r/ F# q/ z: D7 |
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.5 o4 f2 E7 }: g7 D# |. m
另外,可以看看这个:
0 B1 v/ `0 D! m& J$ pUS Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
|