Technical Data
MC68HC11E Family
—
Rev. 4
156
Serial Communications Interface (SCI)
MOTOROLA
Serial Communications Interface (SCI)
TC
—
Transmit Complete Flag
This flag is set when the transmitter is idle (no data, preamble, or
break transmission in progress). Clear the TC flag by reading SCSR
with TC set and then writing to SCDR.
0 = Transmitter busy
1 = Transmitter idle
RDRF
—
Receive Data Register Full Flag
This flag is set if a received character is ready to be read from SCDR.
Clear the RDRF flag by reading SCSR with RDRF set and then
reading SCDR.
0 = SCDR empty
1 = SCDR full
IDLE
—
Idle Line Detected Flag
This flag is set if the RxD line is idle. Once cleared, IDLE is not set
again until the RxD line has been active and becomes idle again. The
IDLE flag is inhibited when RWU = 1. Clear IDLE by reading SCSR
with IDLE set and then reading SCDR.
0 = RxD line active
1 = RxD line idle
OR
—
Overrun Error Flag
OR is set if a new character is received before a previously received
character is read from SCDR. Clear the OR flag by reading SCSR
with OR set and then reading SCDR.
0 = No overrun
1 = Overrun detected
NF
—
Noise Error Flag
NF is set if majority sample logic detects anything other than a
unanimous decision. Clear NF by reading SCSR with NF set and then
reading SCDR.
0 = Unanimous decision
1 = Noise detected