TSTriple() usage

[jimmymagemtek]

Hi Sir, As the line of code below,

    ts_sda = TSTriple(1)

ts_sda then has three attributes: ts_sda.i ts_sda.o ts_sda.oe Why do I see in some example code that ts_sda.oe is used as the output port, instead of ts_sda.o ?

What do they really represent respectively? I can't tell even after see the definition in specials.py

Thanks. Jimmy

[fallen]

I don't know which code you are referring to @jimmymagemtek but oe is the "output enabled" and o is the "output value".

But if in some specific case, for instance an I2C bus where lines are Open Drain with an on-board pull-up, you can just hard wire .o to 0 and only drive .oe to 1 when you want to output a 0 and drive .oe at 0 when you don't want to drive the output (which therefore will rise to a 1 because of the pull-up).

That's maybe why you sometimes see that only .oe is driven to different values.

But:

• oe is output enable
• o is output value
• i is input value