At 10:58 AM 1/24/03 -0800, Tal wrote: >Can an input of a PIC be connected directly to VDD to set a High level ? >What about other digital IC's such as 74HCXXX or FPGA's ? > >One of my guys here insists that input should be tied to VDD through a >resistor. Your guy is correct. Think about what happens if, somehow, that PIC pin gets turned into an output. Many things can cause this - an ESD event that corrupts the TRIS register is only one such possibility. In general, input only pins on CMOS devices can tie directly to GND or VDD without intervening resistors. Un-used pins on TTL devices should tie HI via a 1K or so resistor. The way I prefer to deal with un-used I/O PIC pins is to leave them un-connected and set as outputs. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.