1 Reply Latest reply on Feb 16, 2011 12:06 PM by Felix_M

    bldk & Intel SCH message Network

    Green Belt


      I'm tring to read PMA base haddress in order to throttle the cpu clock (Z510 / U15W) by bios.

      Reference data sheet is :

      Intel® System Controller Hub 
      (Intel® SCH)
      External Design Specification (EDS)
      May 2010
      Revision 2.21


      To issue the read on Intel Sch Message Network I'm doing:


        // Intel SCH Message Network (offset 0x70 port 4)
        // opcode       = 0xD0 (read)
        // target port  = 0x04
        // Reg. Address = 0x70
        // Byte Enable  = 0x00
        pciwrite32(0, 0, 0, 0xd4, 0x00000000);  // Set MDR = 0
        pciwrite32(0, 0, 0, 0xd0, 0xd0047000);  // Issue Read command MCR
        data32 = pciread32(0, 0, 0, 0xd4);
        sprintf(buffer, "HOST BRIDGE PMBA = 0x%08X\n\r", data32);


      The return code is always 0x4 (data32) what's wrong?


      Best Regards

        • Re: bldk & Intel SCH message Network
          Felix_M BlackBelt

          Wecome to the Intel® Embedded Community.


          I want to make you aware of a special place to go with questions like yours.  The Intel® e-Help desk is staffed by Intel representatives who support select Intel embedded platforms including Intel Atom™ and SCH.


          To access e-Help, you need to be a Privileged member of the Intel® Embedded Community.  

          If you are not already a Privileged member, you can request an upgrade to your community account here:




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          I hope this helps.




          J. Felix McNulty

          Community Moderator (Intel contractor)