Communication is important for Embedded System which can use for many application including Internet of Things (IOT).
Communication has 3 type
- Simplex: One way communication , Listening radio, watch TV, read a book
- Half Duplex: two ways communication, cannot communicate at the same time, Walkie-talkie
- Full Duplex: two ways communication at the same time, telephone
Communication can separate to two type of Signal
- Analog Communication: communication by use Analog Signal or natural signal, smoke signal, human conversation
- Digital Communication: communication by use Digital Signal which made by human, 0 or 1 signal, Internet
Communication can separate to two type of interface
- Parallel Communication : Communication sending many bit at the same time
- Serial Communication: Communication sending each bit at a time
Serial vs Parallel Communication
Parallel communication is like 10 lens road, support many cars but use a lot of resource, high speed.
Serial Communication is like one road on rural area, low cost.
In real world, mostly use Serial Communication, because use I/O less than Parallel communication and also easy to implement, program handle each bit at a time. Parallel use more I/O, which mean more speed, but difficult to design, when high speed made cross talk noise.
Even though, it use advantage of Serial and Parallel communication, it is PCI-Express implement by combine many serial, PCI 16x mean Serial 16 channel.