User manual

MCF51QE128 MCU Series Reference Manual, Rev. 3
296 Freescale Semiconductor
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15.1.5 Block Diagram
Figure 15-3 shows the transmitter portion of the SCI.
Figure 15-3. SCI Transmitter Block Diagram
H 8 7 6 5 4 3 2 1 0 L
SCID – Tx Buffer
(Write-Only)
Internal Bus
Stop
11-BIT Transmit Shift Register
Start
SHIFT DIRECTION
lsb
1 × Baud
Rate Clock
Parity
Generation
Transmit Control
Shift Enable
Preamble (All 1s)
Break (All 0s)
SCI Controls TxD
TxD Direction
TO TxD
Pin Logic
Loop
Control
To R eceive
Data In
To TxD P i n
Tx Interrupt
Request
LOOPS
RSRC
TIE
TC
TDRE
M
PT
PE
TCIE
TE
SBK
T8
TXDIR
Load From SCIxD
TXINV
BRK13