ELM621 Datasheet | ELM Electronics

ELM621 Serial Three Bit Port Description The ELM621 is a serially controlled, three bit parallel I/O port in an 8 pin package. The high level of integration employed means that very few external ponents are required in order to construct a fully functional circuit with this IC. The ELM621 offers several convenient Features that many users will appreciate. The provision of a 16 byte buffer allows mands to be chained and executed sequentially with one key stroke. The controllable pullup resistor on the bit 3 port pin is particularly helpful when interfacing to mechanical switches, while the ability to control character echo reduces overhead while operating under puter control....