4.2. Plug and Play Register Summary
Plug and Play card standard register space is divided into three parts; card control, logical device control, and logical device configuration. There is exactly one of each card control register on each ISA card. Card control registers are used for global functions that control the entire card. Logical device control registers and logical device configuration registers are repeated for each logical device. Logical device control registers control device functions, such as enabling the device onto the ISA bus. Logical device configuration registers are used to program the device's ISA bus resource use. There are several vendor defined registers in all three register locations so vendors may configure non-standard ISA resources through the Plug and Play mechanism as well.
Figure 6. Plug and Play High-Level Register Map