Hi, My following 2 queries is regarding the PIC17C42A (rather PIC17CXX) series. 1. When the TMR3 control register is configured for one period and one capture register and the f a Capture event occurs on CAP2 pin will the CA2IF and RBIF both get set? 2. If the pin TCLK12 is set for external clock input, will the PORT B cause interrupt everytime clock pulse is applied to this pin, ie will RBIF get set everytime? If somebody can help me understand the PORT B behaviour more cleary it would just GREAT. Tejpal. ~~~~~~~~~ ------------------------- Tejpal Singh, River Run Software Group 4815 Emperor Blvd. #100 DURHAM, NC 27703 (USA) Ph# (919) 941-0722 Fax# (919) 941-0527 -------------------------