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A program may use IOs for input and output. A input can be read via IO, which can be a port with (multiple) IOs each IO reads a symbol (a bit or more when you have a ADC). Or it can come from fram...
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## A program may use IOs for input and output. A input can be read via IO, which can be a port with (multiple) IOs each IO reads a symbol (a bit or more when you have a ADC). Or it can come from frames, such as UART frames, I2C, SPI, Ethernet, .... (any bus you like). And Output can be done the same but reversed.