MC68HC705MC4 Datasheet, PDF (83/99 Pages) Motorola, Inc – Microcontrollers

MC68HC705MC4 Specification Rev. 1.5
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
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 one
(address mark) in the most significant bit position of a received character or an
idle condition of the PD5/RDI pin. Reset has no effect on the WAKE bit.
1 = Address mark wakeup
0 = Idle line wakeup
10.5.3 SCI Control Register 2 (SCCR2)
SCI control register 2 has the following functions:
• Enables the SCI receiver and SCI receiver interrupts
• Enables the SCI transmitter and SCI transmitter interrupts
• Enables SCI receiver idle interrupts
• Enables SCI transmission complete interrupts
• Enables SCI wakeup
• Transmits SCI break characters
7
6
5
4
3
2
1
0
SCCR2
$000C
READ
WRITE
TIE
TCIE
RIE
ILIE
TE
RE TWU SBK
RESET: 0
0
0
0
0
0
0
0
Figure 10-6: SCI Control Register 2 (SCCR2)
TIE — Transmit Interrupt Enable
This read/write bit enables SCI interrupt requests when the TDRE bit becomes
set. Reset clears the TIE bit.
1 = TDRE interrupt requests enabled
0 = TDRE interrupt requests disabled
TCIE — Transmission Complete Interrupt Enable
MOTOROLA
Page 74
Section 10: Serial Communications Interface