The user implementing the low level UART driver must consider the following
components in mind:
- Jitter buffer - An internal buffer (minimum of 4 bytes size) responsible to
store the bytes sent by the SimpleLink device until the host read operation
starts. The host driver is informed on new data reception upon character
detection on the RX UART line, and is expected to start its read operation
immediately afterwards.
- SW Flow Control Manager – The SimpleLink device requires the UART to use
hardware flow control. In some low-cost controllers, there is no support for
hardware flow control in their UART peripheral. In these cases, the user
must implement software flow control that protects the jitter buffer from
being overridden, by asserting the RTS line before it gets full, and follows
the CC31XX device flow control state by testing the CTS line before sending
any data.
- Active Buffer – points to the current buffer to accept the incoming bytes.
At the beginning of received message points to the jitter buffer, and upon
UART read operation start is switched to the host driver supplied one.