Specifications

AMD Geode™ GeodeROM Functional Specification 77
PCI Support
32087C
7.1.3 Subfunction 03h - Find PCI Class Code
Description:
The function Find PCI Class Code returns the Nth occurrence of the device or device function whose class code
matches the value passed in the ECX register.
The Find PCI Class Code function is useful for locating all system PCI devices that belong to the same device class.
The first return value of DEVICE_NOT_FOUND indicates there are no more devices in the system with the specified
class code.
Passed:
Returns:
Parameter Description
AH B1h (PCI Function ID)
AL 03h (Find PCI Class Code)
ECX Class code in lower three bytes
SI Index N (Nth occurrence of PCI device or function whose class code matches that passed in the ECX
register)
Parameter Description
BH Bus number of device (0-based)
BL Bits [7:3] = Device number
Bits [2:0] = Function number within located device
CF Function completion status:
0 if device was located
1 if an error occurred, AH contains error code
AH Function return status codes: See AH in Section 7.1.2 "Subfunction 02h - Find PCI Device" on page
76.