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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:
, Z' F3 u" w9 a) Q5 T5 nThe firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.
W5 ~: R9 \9 N' a" k. W, DThis interface consists of four bi-directional signals and one control input. The timing and electrical6 ] J9 ]' ]3 R; E! L& Y% Z
parameters of the FWH interface are similar to those of the LPC interface, to provide compatibility
' \" n; z+ U7 M3 p% M& Z; lbetween the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as
6 i3 [# Z. J; D( pwell as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,
( E: ~4 g/ t6 r1 B+ zwhich allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The
8 j! M$ X5 M) Z5 `" p% ]% A7 OIntel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code.
* S8 q- J1 n7 T# `This ensures that all LPC devices present on the shared interface will ignore cycles destined for the
; g0 O! I* F' l! mFWH, without becoming confused by the different protocol.
" O9 s6 H* y* @3 p2 v( ]+ G$ ^FWH和LPC基本是兼容的,不过FWH比LPC多几组命令 z6 n3 U: U4 F! K# C8 N: T$ p
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.
. C/ Z4 ]6 l5 i2 s" Q0 X# \另外,可以看看这个:
# \7 a3 y( }$ DUS Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
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