Analog Devices EV-SC598-SOM, Руководство пользователя

Страница: 22 / 33

Figure 3-5:
Example of a Mechanical Switch (Equivalent to Example of Bus Switch)
SoftConfig on the Board
Microchip MCP23018 GPIO expanders provide control for individual electronic switches. The TWI2 interface of
the processor communicates with the Microchip devices. There are individual switches with default settings that en-
able 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 Availability by Default
UART0 USB to UART FTDI232RQ
SPI Flash Quad mode enabled
eMMC eMMC device enabled, eMMC to SOM Interface J2 disabled
LEDs Enabled
Programming SoftConfig Switches
On the board, a Microchip MCP23018 devices exist. Each of these devices have the following programming charac-
teristics:
•
Each GPIO register controls eight signals (software switches).
Software-Controlled Switches (SoftConfig)
3–6
EV-SC598-SOM
®
Manual