MC68HC05C8A Datasheet, PDF (79/158 Pages) Motorola, Inc – Microcontrollers

Serial Communications Interface (SCI)
SCI Input/Output (I/O) Registers
Address: $000E
Bit 7
6
5
4
3
2
1
Bit 0
Read: R8
T8
0
M
WAKE
0
0
0
Write:
Reset:
Unaffected by reset
= Unimplemented
Figure 9-5. SCI Control Register 1 (SCCR1)
R8 — Bit 8 (Received)
When the SCI is receiving 9-bit characters, R8 is the ninth bit of the
received character. R8 receives the ninth bit from the receive shift
register at the same time that the SCDR receives the other eight bits.
Reset has no effect on the R8 bit.
T8 — Bit 8 (Transmitted)
When the SCI is transmitting 9-bit characters, T8 is the ninth bit of the
transmitted character. T8 is loaded into the transmit shift register at
the same time that SCDR is loaded into the transmit shift register.
Reset has no effect on the T8 bit.
M — Character Length Bit
This read/write bit determines whether SCI characters are 8 bits long
or 9 bits long. The ninth bit can be used as an extra stop bit, as a
receiver wakeup signal, or as a mark or space parity bit. Reset has no
effect on the M bit.
1 = 9-bit SCI characters
0 = 8-bit SCI characters
WAKE — Wakeup Bit
This read/write bit determines which condition wakes up the SCI: a
logic 1 (address mark) in the most significant bit position of a received
character or an idle condition of the PD0/RDI pin. Reset has no effect
on the WAKE bit.
1 = Address mark wakeup
0 = Idle line wakeup
MC68HC05C8A • MC68HCL05C8A • MC68HSC05C8A — Rev. 5.0
MOTOROLA
Serial Communications Interface (SCI)
Technical Data
79