The purpose of the IC660BBD023 bus configuration space is to provide a suitable set of configuration devices that meet the needs of current and future system configuration characteristics. The configuration space is an address space with a capacity of 256 B and a specific record structure. The space is divided into two parts: the header area and the equipment related area. The configuration space of a device can be accessed not only during system bootstrapping, but also at any other time. Software must use I/O to access device configuration space through memory access.

The various fields in the header area are used to uniquely identify the device and enable it to be controlled using general methods. The header area has 64 B, divided into two parts: the definition of the first 16 B is the same for any type of device, and the remaining 48 B varies depending on the supported functions of each device.

Devices based on the IC660BBD023 bus must provide manufacturer ID, device ID, fallacy, and status within the header area. The settings of other registers can be selected based on the device’s functionality (such as being reserved registers).

Any register that varies by device is not in this header area and must be arranged in the address space corresponding to 64 to 255. Some of the multi byte data fields are reserved for future use, and software must handle them carefully and correctly. When reading, the IC660BBD023 software must extract defined bits with appropriate masking, and when performing write operations, the software must ensure that the value of the reserved bits does not change.