Datasheet

ADSP-BF609 EZ-KIT Lite Evaluation System Manual 2-9
ADSP-BF609 EZ-KIT Lite Hardware Reference
• By default, the Microchip MCP23017 GPIO signals function as
input signals.
The signals must be programmed as output signals to override their
default values. The following table shows the Microchip register
addresses and the values that must be written to them to program
the signals as output signals.
Each of the examples in Cross Core Embedded Studio include source files
that program the soft switches, even if the default settings are being used.
The
README for each example identifies only the signals that are being
changed from their default values. The code that programs the soft
switches is located in the SoftConfig_BF609.c file in each example.
The following tables (Table 2-2, Table 2-3, and Table 2-4) outline the
default values for each of the three Microchip MCP23017 devices.
IODIR Register IODIR Register Address Value to be Written to Program Signals
as Outputs
IODIRA 0x00 0
IODIRB 0x01 0
Table 2-2. I
2
C Hardware Address 0x21
GPIO MCP23017 Register Address Default Value
GPIOA 0x12 0x07
GPIOB 0x13 0xFC
Table 2-3. I
2
C Hardware Address 0x22
GPIO MCP23017 Register Address Default Value
GPIOA 0x12 0x0A
GPIOB 0x13 0x00