Compaq EN Series Technical Reference Manual page 98

4.7.2.2 87307 I/O Controller Functions
The 87307 I/O controller contains various functions such as the keyboard/mouse interfaces,
diskette interface, serial interfaces, and parallel interface. While the control of these interfaces
uses standard AT-type I/O addressing, the configuration of these functions uses indexed ports
unique to the 87307. In this system, hardware strapping selects I/O addresses 015Ch and 015Dh
at reset as the Index/Data ports for accessing the logical devices within the 87307. The hardware
strapping also places the 87307 into PnP motherboard mode. The integrated logical devices are
listed as follows:
Table 4-22 lists the PnP standard control registers for the 87307.
Table 4–22. 87307 I/O Controller PnP Standard Control Registers
87307 I/O Controller PnP Standard Control Registers
Index Function
00h Set RD_DATA Port
01h Serial Isolation
02h Configuration Control
03h Wake (CSN)
04h Resource Data
05h Status
06h Card Select Number (CSN)
07h Logical Device Select:
00h = 8042 Controller (Keyboard I/F)
01h = 8042 Controller (Mouse I/F)
02h = RTC/APC Configuration
03h = Diskette Controller
04h = Parallel Port
05h = UART 2 (Serial Port B / IrDA)
06h = UART 1 (Serial Port A)
07h = GPIO Ports
08h = Power Management
20h Super I/O ID Register (SID)
21h SIO Configuration 1 Register
22h SIO Configuration 1 Register
23h Programmable Chip Select Configuration Index
24h Programmable Chip Select Configuration Data
NOTE:
For a detailed description of registers refer to appropriate National documentation.
The configuration registers are accessed by writing the appropriate logical device's number to
index 07h and writing the desired offset to the index register. The data is then either written to or
read from the data register.
Table 4-22.
Compaq Deskpro EN Series of Personal Computers
Desktop and Minitower Form Factors
Third Edition - September 1998
Technical Reference Guide
Reset Value
00h
00h
00h
00h
A0h
16h
02h
00h
00h
4-49