The TTL-232R-RPi cable provides a USB to
asynchronous serial data transfer path capable of supporting data rates from 300 bits/s to 3 Mbits/s at 3.3 V TTL levels.
The chip handles all the USB signaling and protocol requirements, enabling an improved debug and development environment
where kernel debug messaging can be accessed.
Raspberry Pi Cable, TTL-232R-RPI Datasheet