ADSP-21469 offers 9 GPIO pins for digital I/O -- "flags". But this is not enough for my purposes, I need around 16 inputs.
Are there (external) solutions to expand the number of GPIO pins, with interrupt?
Look at I2C I/O expanders such as TCA6416A. Most provide interrupt on change so you can poll for change only after you already know a pin has changed.
Using three lines SDA, SCL and INT would gain you 16 I/O pins using the part mentioned above.
I routinely use the Microchip MCP23S17 for this kind of application. It is similar to the part Klaus suggested. There are both SPI & I2C versions.
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