Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Table 6-195 Start Dependent Function Priority Byte Definition
Bits Definition
1:0 Compatibility priority. Acceptable values are:
0 Good configuration: Highest Priority and preferred configuration
1 Acceptable configuration: Lower Priority but acceptable configuration
2 Sub-optimal configuration: Functional configuration but not optimal
3 Reserved
3:2 Performance/robustness. Acceptable values are:
0 Good configuration: Highest Priority and preferred configuration
1 Acceptable configuration: Lower Priority but acceptable configuration
2 Sub-optimal configuration: Functional configuration but not optimal
3 Reserved
7:4 Reserved (must be 0)
Notice that if multiple Dependent Functions have the same priority, they are further prioritized by
the order in which they appear in the resource data structure. The Dependent Function that appears
earliest (nearest the beginning) in the structure has the highest priority, and so on.
See Section 19.6.122, “StartDependentFn (Start Dependent Function Resource Descriptor Macro),”
for a description of the ASL macro that creates a Start Dependent Function descriptor.
6.4.2.4 End Dependent Functions Descriptor
Type 0, Small Item Name 0x7, Length = 0
Only one End Dependent Function item is allowed per logical device. This enforces the fact that
Dependent Functions cannot be nested.
Table 6-196 End Dependent Functions Descriptor Definition
Offset Field Name
Byte 0 Value = 0x38 (00111000B) – Type = 0, Small item name = 0x7, Length =0
See Section 19.6.39, “EndDependentFn (End Dependent Function Resource Descriptor Macro,” for
a description of the ASL macro that creates an End Dependent Functions descriptor.
6.4.2.5 I/O Port Descriptor
Type 0, Small Item Name 0x8, Length = 7
There are two types of descriptors for I/O ranges. The first descriptor is a full function descriptor for
programmable devices. The second descriptor is a minimal descriptor for old ISA cards with fixed I/
O requirements that use a 10-bit ISA address decode. The first type descriptor can also be used to
describe fixed I/O requirements for ISA cards that require a 16-bit address decode. This is
accomplished by setting the range minimum base address and range maximum base address to the
same fixed I/O value.
346 April, 2015 Version 6.0