Fes6911, 1) enter the mb pnp mode, 2) modify the data of the registers – Acnodes FES 6911 User Manual

Page 47: 3) exit the mb pnp mode

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FES6911

Fanless Embedded Controller comes with

Intel Atom N270 1.6GHz Processor

There are three steps to complete the configuration setup: (1) Enter the MB PnP Mode; (2)
Modify the data of configuration registers; (3) Exit the MB PnP Mode. Undesired result may occur
if the MB PnP Mode is not exited normally.

(1) Enter the MB PnP Mode

To enter the MB PnP Mode, four special I/O write operations are to be performed during Wait for
Key state. To ensure the initial state of the key-check logic, it is necessary to perform four write
opera-tions to the Special Address port (2EH). Two different enter keys are provided to select
configuration ports (2Eh/2Fh) of the next step.

(2) Modify the Data of the Registers

All configuration registers can be accessed after entering the MB PnP Mode. Before accessing a
selected register, the content of Index 07h must be changed to the LDN to which the register
belongs, except some Global registers.

(3) Exit the MB PnP Mode

Set bit 1 of the configure control register (Index=02h) to 1 to exit the MB PnP Mode.