Software-Controlled Switches (SoftConfig)
2-8
ADSP-CM403F EZ-KIT Lite Evaluation System Manual
Programming SoftConfig Switches
On the ADSP-CM403F EZ-KIT Lite, one Microchip MCP23017 device
exists. The device has the following programming characteristics:
• Each switch has two programmable GPIO registers.
• 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.
Table 2-1. Default ADSP-CM403F Processor Interface Availability
Interface
Availability by Default
UART0
RS-232
RX
,
TX
and
RTS
enabled by default. SoftConfig required for other
functionality.
CAN0
Enabled in hardware, disabled in software to use
LED1
.
Push buttons
Enabled
LEDs
Enabled
GPIO Register
Register Address
GPIOA
0x12
GPIOB
0x13
IODIR Register IODIR Register Address Value to be Written to Program Signals
as Outputs
IODIRA
0x00
0
IODIRB
0x01
0
