mc68hc908gp32 Freescale Semiconductor, Inc, mc68hc908gp32 Datasheet - Page 135

• Manufacturer Part Number: mc68hc908gp32
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

13.4.2 Transmitter
Figure 13-4
The baud rate clock source for the SCI can be selected via the configuration bit, SCIBDSRC. Source
selection values are shown in
13.4.2.1 Character Length
The transmitter can accommodate either 8-bit or 9-bit data. The state of the M bit in SCI control register 1
(SCC1) determines character length. When transmitting 9-bit data, bit T8 in SCI control register 3 (SCC3)
is the ninth bit (bit 8).
Freescale Semiconductor
SL = 0 => SCICLK = CGMXCLK
SL = 1 => SCICLK = BUS CLOCK
BUS CLOCK
CGMXCLK
shows the structure of the SCI transmitter.
SCIBDSRC
CONFIG2
FROM
SL
INTERRUPT REQUEST
TRANSMITTER CPU
X
SCP1
SCP0
SCR2
SCR1
SCR0
÷ 4
SCALER
PRE-
Figure 13-4. SCI Transmitter Block Diagram
Figure
DIVIDER
BAUD
PEN
PTY
MC68HC908GP32 Data Sheet, Rev. 10
13-4.
TXINV
÷ 16
GENERATION
PARITY
SCTE
SCTIE
TC
TCIE
T8
M
H
8
SCTIE
7
SCTE
TCIE
TC
SCI DATA REGISTER
6
SHIFT REGISTER
INTERNAL BUS
TRANSMIT
5
11-BIT
CONTROL LOGIC
4
TRANSMITTER
3
2
1
LOOPS
ENSCI
SBK
TE
0
L
Functional Description
PTE0/TxD
135