ELM621
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. Naturally, individual as well as simultaneous read, set, clear and toggle mands are also supported.
All munications with this device are via a standard 9600 baud RS232 connection, using AT style mands. No special characters are required, so that virtually any terminal program can be used with the ELM621. More advanced users will be interested...
