SIO配置寄存器访问指南.ppt

SIO Configuration Register Access Guide 2009.03.11 Theory After a PCI Reset or Vcc Power On Reset the SIO is in the Run Mode with all logical devices disabled. The logical devices may be configured through two standard Configuration I/O Ports (INDEX and DATA) The key to access the SIO IO space is to check the IO base address. This inforamtion can be get from the SIO data sheet. IO configuration For Current IO chip support the PnP spec, so the configuration register follow the standard PnP configuration spec. or is a subset of the spec. The following is the standard register define for PnP spec. Some Standard Registers Explain For the offset 07, the location is define as the logical device number, and in the datsheet of SIO, the offset has the same define. And the offset 20-2F is used for Vendor, So the datasheet does. So the SIO if support the PnP Mode, they should have the same access rule. The following will list some ite datasheet information to check above conclusion ITE8720 For the offset 07, Logical Device Number 20-2F is used for Vendor define. 20/21 is chip ID 22: chip version SMSC5147 The offset 07: Logical Devce Number. 20: device ID 21: Version ..2F, are device specific Winbond WPCD376H Offset 07: Logical device Number Offset 20/2F: SIO ID registers. Conclusion From above compare, the access to IO configuration space follow the same rule, and common access point can be get from datasheet. And base address is in the following rule: SMSC: 002E 002F or 004E/004F ITE: 002E 002F or 004E/004F WINBOND: 002E 002F or 004E/004F Backup PNP ISA Spec