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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:
' g1 K5 ?: Y6 s9 N; wThe firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.
! U$ o2 e, u5 B% U6 Q; f0 eThis interface consists of four bi-directional signals and one control input. The timing and electrical$ K7 I6 c% c% {0 \
parameters of the FWH interface are similar to those of the LPC interface, to provide compatibility
. u0 V+ g. M2 m5 _" n) k, |between the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as; T; G( a3 I0 U! ?4 r/ U8 b
well as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,
9 t# ^5 x' N6 S+ zwhich allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The- p) H' m# w) M
Intel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code.
6 N* d" ^! r' A5 p& k+ bThis ensures that all LPC devices present on the shared interface will ignore cycles destined for the
# l. p6 R% ~! kFWH, without becoming confused by the different protocol.
7 a& T5 N) I. U' M0 x pFWH和LPC基本是兼容的,不过FWH比LPC多几组命令
. V( }/ c7 [3 r; z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.
; T& }& \8 Z5 z0 [$ _" j; K另外,可以看看这个:: B* p0 j4 y. g( s% p t% x
US Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
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