In SX Microcontrollers, SX/B Compiler and SX-Key Tool, Kurt wrote:

can you explain in more detail what the below text mean??

"
To distill what Bean is saying, when operating an open collector bus (which I2C is), instead of changing the data in the register, you instead change the pin direction from input to output and vice versa. When you set up the pin, you write a 0 to the bit(s) and you never change it(them) again. When you want the output to be 1, set the pin's direction to input. When you want the output to be 0, you set the pin's direction to output. The key is allowing the external pullup resistor to supply the 1 value.

Its handy that the SX's pin direction definition is identical to what the data on the bus is, a 1 in the pin direction is a 1 on the bus, and a 0 in the pin direction is a 0 on the bus."


Kurt

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