MC68HC05C8A Datasheet, PDF (83/158 Pages) Motorola, Inc – Microcontrollers

Serial Communications Interface (SCI)
SCI Input/Output (I/O) Registers
Reset sets the TC bit. Software must initialize the TC bit to logic 0 to
avoid an instant interrupt request when turning on the transmitter.
1 = No transmission in progress
0 = Transmission in progress
RDRF — Receive Data Register Full Bit
This clearable, read-only bit is set when the data in the receive shift
register transfers to the SCI data register. RDRF generates an
interrupt request if the RIE bit in SCCR2 is also set. Clear the RDRF
bit by reading the SCSR with RDRF set, and then reading the SCDR.
Reset clears the RDRF bit.
1 = Received data available in SCDR
0 = Received data not available in SCDR
IDLE — Receiver Idle Bit
This clearable, read-only bit is set when 10 or 11 consecutive logic 1s
appear on the receiver input. IDLE generates an interrupt request if
the ILIE bit in SCCR2 is also set. Clear the IDLE bit by reading the
SCSR with IDLE set, and then reading the SCDR. Reset clears the
IDLE bit.
1 = Receiver input idle
0 = Receiver input not idle
OR — Receiver Overrun Bit
This clearable, read-only bit is set if the SCDR is not read before the
receive shift register receives the next word. OR generates an
interrupt request if the RIE bit in SCCR2 is also set. The data in the
shift register is lost, but the data already in the SCDR is not affected.
Clear the OR bit by reading the SCSR with OR set and then reading
the SCDR. Reset clears the OR bit.
1 = Receiver shift register full and RDRF = 1
0 = No receiver overrun
NF — Receiver Noise Flag
This clearable, read-only bit is set when noise is detected in data
received in the SCI data register. Clear the NF bit by reading the
SCSR and then reading the SCDR. Reset clears the NF bit.
1 = Noise detected in SCDR
0 = No noise detected in SCDR
MC68HC05C8A • MC68HCL05C8A • MC68HSC05C8A — Rev. 5.0
MOTOROLA
Serial Communications Interface (SCI)
Technical Data
83