Analog Devices ADZS-21569-EZKIT Manual page 22

Software-Controlled Switches (SoftConfig)
Figure 3-5: Example of a Mechanical Switch (Equivalent to Example of Bus Switch)
SoftConfig on the Board
Two Microchip MCP23017 GPIO expanders provide control for individual electronic switches. The TWI2 inter-
face of the processor communicates with the Microchip devices. There are individual switches with default settings
that enable basic board functionality.
The Default Processor Interface Availability table lists the processor and board interfaces that are available by de-
fault. Note that only interfaces affected by software switches are listed in the table.
Table 3-1: Default Processor Interface Availability
Interface
UART0
SPI Flash
Audio Connectors
S/PDIF Digital
Pushbuttons
LEDs
Programming SoftConfig Switches
On the board, two Microchip MCP23017 devices exist. Each of these devices have the following programming
characteristics:
• Each GPIO register controls eight signals (software switches).
3–6
Availability by Default
USB to UART FTDI232RQ
Quad mode enabled
4 inputs/8 outputs
S/PDIF RCA input and output connectors enabled
Enabled
Enabled
ADZS-21569-EZKIT Manual