Chip Com Notes

Main Types

• UART: universal asynchronous receiver/transmitter
• I2C:
• SPI: serial peripherial interface

SPI (spy)

Very loose standard.

• MISO: master-in slave-out
• MOSI: master-out slave-in
• clock: slave will read on either rise or fall.
• slave select: generally inactive is high. one per slave (could be done with serial-to-parllel)

I2C

2 lines

• clock
• data

Both are bidirectional and open drain. Data is sent while the clock is low, control is sent when the clock is high. The first thing that is sent is a slave address 7-bits then 1 bit for read or write. Slave sends awk.