Hi all Does any one know why PORT0.27 at LPC1768 is open drain?when i add external 10k pull up resistor then this pin work properly but when i remove external resistor it doesnt work and for example if i apply high level via LPC_GPIO0->FIOSET|=(1<<27); then this pin goes to 0.3volt instead of 3.3volt and when apply low level via LPC_GPIO0->FIOCLR|=(1<<27); it goes to 0 volt. I enable chip pull up resistor on this pin but it seems doesnt work.What should i do?
The designers of the chip would know - but it has nothing to do with Keil!
So you need to ask NXP
http://community.nxp.com/
www.nxp.com/.../512kb-flash-64kb-sram-ethernet-usb-lqfp100-package:LPC1768FBD100?tab=Design_Support_Tab
Thank you