HI!
GIO default status is input after reset, in fact , those gio should be pulled up or pulled down in design. many soc can set pull up or pull down register or disable pull up or pull down. how about gio on DM355,I cannot find any register about pull up or pull down? but in approtch Dm355 ip camera schmatic, R/B pin of nandflash is not pulled up by external resister, we know this R/B pin is an OC gate, if GIO cannot pulled up by internal resister , an external resister must be pulled up, but,in fact, there is no any external resistor on its design. but it still works fine. it is very strange. but in my design, I copy appro design, no external resister just like approtech, it doesn't work. I have to add an extra resistor pulled by 3.3V, and then it is ok.
Can anybody give me some explaination?
