2. Configure the Configuration Registers
3. Exit Configuration Mode.
The desired configuration registers are accessed
in two steps:
a. Write the index of the Logical Device Number
Configuration Register (i.e., 0x07) to the
INDEX PORT and then write the number of the
desired logical device to the DATA PORT
b. Write the address of the desired configuration
register within the logical device to the INDEX
PORT and then write or read the configuration
register through the DATA PORT.
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 a write of 0x55 data to
the CONFIG PORT. Once the initiation key is
received correctly the chip enters into the
Configuration State (The auto Config ports are
enabled).
Note: if accessing the Global Configuration
Registers, step (a) is not required.
Configuration Mode
Exit 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.
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.
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