FSI module supports detection of data overrun or underrun conditions.

• Receive buffer Overrun - This event indicates that the transfer of data from receive shift register to receiver data buffer register overwrites unread data already in received data.
• Receive buffer Underrun – This event indicates that software reads the buffer while it is empty
• Transmit buffer Overrun – This event occurs if a piece of data is overwritten before it has been transmitted.
• Transmit buffer Underrun – This event occurs when the transmitter tries to read data from a location which has not yet been written.

A flag bit is set and an interrupt is generated when data overrun/underrun error occurs and corresponding register bit is enabled.