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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:
( G9 L4 Q! E/ o. V' sThe firmware hub relies on the Intel Firmware Hub interface to communicate with the outside world.* h7 i) `) o$ O0 N" j
This interface consists of four bi-directional signals and one control input. The timing and electrical
2 \4 E. `2 W) O* y7 Yparameters of the FWH interface are similar to those of the LPC interface, to provide compatibility1 m0 f! o6 c6 Y
between the interfaces, but differ in cases mentioned earlier in this section (clock pin capacitance), as
6 u' F6 D& B+ S; c- M3 L! d- T7 Dwell as in certain timing parameters. The Intel ICH has been engineered to accommodate both interfaces,4 y3 r) w3 K: k, d' ?/ X
which allows the Intel FWH interface signals to be communicated over the same set of pins as LPC. The
& t5 T7 A" V( X5 D6 GIntel FWH interface is designed to use an LPC-compatible start cycle, with a reserved cycle type code.
+ A( M2 U9 V' j; ?( ^( rThis ensures that all LPC devices present on the shared interface will ignore cycles destined for the2 C8 R( w7 g8 c" D: S: ~
FWH, without becoming confused by the different protocol.9 s) s! \4 F/ }4 r
FWH和LPC基本是兼容的,不过FWH比LPC多几组命令( @2 Z) z8 R; \9 ]
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.
K$ K5 k9 ^ T另外,可以看看这个:
4 K( e; q6 ]% w( `$ T1 h/ \US Patent 7249213 - Memory device operable with a plurality of protocols with configuration data stored in non-volatile storage elements |
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