Part Number: TMS320F280049 hello, My question is very similar to this question. " e2e.ti.com/.../793067 I ran into the same problem with GPIO39 on TMS320F280049 . GPIO39 is configured as input IO, internal pullup is unused. there is a 4.7K pull-up resistor externally, a little far away from the DSP pin. My "buffer" circuit is composed of an optocoupler and a 4.7K pull-up resistor. sometimes , when the primary side of the optocoupler input signal is “high”, Optocoupler secondary side does not conduct, output signal should be high level. but The status of IO in software register is 0， and output signal is low level signal. it means that GPIO39 Internally forced the signal to the low. this phenomenon is random. Can you explain why this happens and how to fix it? thank you.
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