ICs (Integrated Circuits)
DIL (Dual-In-Line) Package:
Pin 1 can be identified by a spot or notch on the package, as well as the orientation of the writing on it. The pins are numbered anticlockwise (see diagram below).
PLCC (Plastic Leaded Chip Carrier) Package:
Holding the device with the cut-off corner at the top left, pin 1 is in the middle of the top row of pins and is identified by a spot on the package. The pins are numbered anticlockwise from this point (see diagram below).
PQFP / MQFP (Quad Flat Pack) Package:
With the cut-off corner in the top left-hand corner, pin 1 is at the top of the left-hand row of pins. The pins are numbered anticlockwise from this point.
