|
|
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:
8 o" w+ S K4 k0 |/ b( `' XThe firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.. V, g: _# L7 `- ], `, |
This interface consists of four bi-directional signals and one control input. The timing and electrical
3 x% D2 ^ ]- x0 P: C! v6 K: Oparameters of the FWH interface are similar to those of the LPC interface, to provide compatibility
3 \, ^; u7 q3 e& h/ B3 Bbetween the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as
9 P# f$ ?5 g4 i4 n6 dwell as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,0 T: \; L z. F' p
which allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The
& o ~; H, v1 }/ i. aIntel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code.
7 T5 G" U( d" G; RThis ensures that all LPC devices present on the shared interface will ignore cycles destined for the3 B8 O6 _* ?" d" {9 ?
FWH, without becoming confused by the different protocol.
5 W( l0 `& s2 r( ?$ a, @( _FWH和LPC基本是兼容的,不过FWH比LPC多几组命令' u0 A7 x1 a: o; s$ C: L
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.
# `6 }8 B4 S" m+ E h( z( {9 A另外,可以看看这个:
( Q; d- _( R+ W5 i1 h% e2 `US Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
|