W83637HF Datasheet, PDF (103/149 Pages) Winbond – LPC I/O

W83637HF
8. CONFIGURATION REGISTER
8.1 Plug and Play Configuration
The W83637HF uses Compatible PNP protocol to access configuration registers for setting up different
types of configurations. In W83637HF, there are eleven Logical Devices (from Logical Device 0 to
Logical Device B with the exception of logical device 4 for backward compatibility) which correspond to
eleven individual functions: FDC (logical device 0), PRT (logical device 1), UART1 (logical device 2),
UART2 (logical device 3), KBC (logical device 5), CIR (Consumer IR, logical device 6), GPIO1 (logical
device 7), GPIO2 (logical device 8), GPIO3 (logical device 9), ACPI ((logical device A), and hardware
monitor (logical device B). Each Logical Device has its own configuration registers (above CR30).
Host can access those registers by writing an appropriate logical device number into logical device
select register at CR7.
8.1.1 Compatible PnP
8.1.1.1 Extended Function Registers
In Compatible PnP, there are two ways to enter Extended Function and read or write the configuration
registers. HEFRAS (CR26 bit 6) can be used to select one out of these two methods of entering the
Extended Function mode as follows:
HEFRAS
0
1
Address and Value
Write 87h to the location 2Eh twice
Write 87h to the location 4Eh twice
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Publication Release Date: June 25, 2003
Revision 1.3