ADSP-SC589 EZ-Board® Evaluation System Manual
31
Default ADSP-SC589 Processor Interface Availability
LEDs
Enabled
3.2.3 Programming SoftConfig Switches
On the ADSP-SC589 EZ-Board, two Microchip MCP23017 devices exist. Each of these devices have
the following programming characteristics:
Each switch has two programmable GPIO registers.
GPIO Register Register Address
GPIOA
0x12
GPIOB
0x13
Each GPIO register controls eight signals (software switches).
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.
IODIR Register IODIR Register Address
Value to be Written to Program Signals as Outputs
IODIRA
0x00
0
IODIRB
0x01
0
Each of the examples in the ADSP-SC58x Board Support Package 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_SC589.c file in each example.
The following tables outline the default values for each of the two Microchip MCP23017 devices.
GPIO
MCP23017 Register Address
Default Value
GPIOA
0x12
0xE0
GPIOB
0x13
0x00
