s908qc16vdse Freescale Semiconductor, Inc, s908qc16vdse Datasheet - Page 127

• Manufacturer Part Number: s908qc16vdse
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

13.3.2.3 Break Characters
Writing a 1 to the send break bit, SBK, in SCC2 loads the transmit shift register with a break character.
For TXINV = 0 (output not inverted), a transmitted break character contains all 0s and has no start, stop,
or parity bit. Break character length depends on the M bit in SCC1 and the LINR bits in SCBR. As long
as SBK is set, transmitter logic continuously loads break characters into the transmit shift register. After
software clears the SBK bit, the shift register finishes transmitting the last break character and then
transmits at least one 1. The automatic 1 at the end of a break character guarantees the recognition of
the start bit of the next character.
When LINR is cleared in SCBR, the ESCI recognizes a break character when a start bit is followed by
eight or nine 0 data bits and a 0 where the stop bit should be, resulting in a total of 10 or 11 consecutive
0 data bits. When LINR is set in SCBR, the ESCI recognizes a break character when a start bit is followed
by 9 or 10 0 data bits and a 0 where the stop bit should be, resulting in a total of 11 or 12 consecutive 0
data bits.
Freescale Semiconductor
BUS CLOCK
BUSCLKX4
OR
PSSB4
PSSB3
PSSB2
PSSB1
PSSB0
PDS2
PDS1
PDS0
SCP1
SCP0
SCR2
SCR1
SCR0
÷
INTERRUPT REQUEST
4
TRANSMITTER
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 4
SCALER
PRE-
DIVIDER
BAUD
PEN
PTY
Figure 13-4. ESCI Transmitter
TXINV
÷
GENERATION
16
PARITY
SCTE
SCTIE
TC
TCIE
T8
M
STOP
8
SCTIE
7
SCTE
TCIE
TC
ESCI DATA REGISTER
6
SHIFT REGISTER
INTERNAL BUS
TRANSMIT
5
11-BIT
4
CONTROL LOGIC
TRANSMITTER
3
2
1
LOOPS
ENSCI
LINT
SBK
TE
0
START
Functional Description
SCI_TxD
127