FDC37M81 SMSC [SMSC Corporation], FDC37M81 Datasheet - Page 134

• Manufacturer Part Number: FDC37M81
• Description: PC98/99 Compliant Enhanced Super I/O Controller with Keyboard/Mouse Wake-Up
• Manufacturer: SMSC [SMSC Corporation]

CONFIGURATION SEQUENCE
To program the configuration registers, the
following sequence must be followed:
Enter Configuration Mode
To place the chip into the Configuration State
the Config Key is sent to the chip's CONFIG
PORT. The config key consists of 0x55 written
to the CONFIG PORT. Once the configuration
key is received correctly the chip enters into the
Configuration State (The auto Config ports are
enabled).
Configuration Mode
The system sets the logical device information
and activates desired logical devices through
the INDEX and DATA ports. In configuration
mode, the INDEX PORT is located at the
CONFIG PORT address and the DATA PORT is
at INDEX PORT address + 1.
1. Enter Configuration Mode
2. Configure the Configuration Registers
3. Exit Configuration Mode.
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The desired configuration registers are accessed
in two steps:
a. Write the index of the Logical Device
b. Write
Note: If accessing the Global Configuration
Registers, step (a) is not required.
Exit Configuration Mode
To exit the Configuration State the system writes
0xAA to the CONFIG PORT. The chip returns
to the RUN State.
Note: Only two states are defined (Run and
Configuration). In the Run State the chip will
always be ready to enter the Configuration
State.
Number Configuration Register (i.e., 0x07) to
the INDEX PORT and then write the number
of the desired logical device to the DATA
PORT
configuration register within the logical
device to the INDEX PORT and then write or
read the configuration register through the
DATA PORT.
the
address
of
the
desired