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发表于 2008-10-21 16:23:13
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In burst mode, embedded controller has received the burst enable command from the host, has halted normal processing, and is waiting for a series of commands to be sent from the host. this allows OSPM or system management handler to quickly read and write several bytes of data at a time without the overhead of SCIs between the commands. 4 _+ X( B9 g' Q. v
一般情况下, OSPM与EC通信均是通过SCIs事件方式(interrupt-driven command processing)来完成, 但当在需要传输比较多数据时, 如SMBus Block 的大量数据传输时, OSPM可以发送 Bust Enable Command 请求EC进入burst Mode, 在此模式下, EC将中止正常的其它处理, 只处理与 OSPM 进行的全速的读/写操作, 此时, 不再是以SCIs事件来触发每一次的读写,而是查询方式(polled command processing)进行, 但这样处理不能超过 1ms:
. i4 \ A8 X+ z# y& E• First Access – 400 microseconds5 ^6 }* O0 h* e5 d1 D o- }8 C
• Subsequent Accesses – 50 microseconds each
( a; Z3 y; Q4 K3 \: j• Total Burst Time – 1 millisecond7 J0 m; }# J3 ^
当EC在收到 OSPM 发送的 Bust Disable Command 后, 则结束 Burst mode. |
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