s908gr32ag3vfa Freescale Semiconductor, Inc, s908gr32ag3vfa Datasheet - Page 156

• Manufacturer Part Number: s908gr32ag3vfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Enhanced Serial Communications Interface (ESCI) Module
13.4.2 Transmitter
Figure 13-5
The baud rate clock source for the ESCI can be selected via the configuration bit, SCIBDSRC.
13.4.2.1 Character Length
The transmitter can accommodate either 8-bit or 9-bit data. The state of the M bit in ESCI control
register 1 (SCC1) determines character length. When transmitting 9-bit data, bit T8 in ESCI control
register 3 (SCC3) is the ninth bit (bit 8).
13.4.2.2 Character Transmission
During an ESCI transmission, the transmit shift register shifts a character out to the TxD pin. The ESCI
data register (SCDR) is the write-only buffer between the internal data bus and the transmit shift register.
156
BUS CLOCK
CGMXCLK
OR
shows the structure of the SCI transmitter and the registers are summarized in
PSSB4
PSSB3
PSSB2
PSSB1
PSSB0
PDS2
PDS1
PDS0
SCP1
SCP0
SCR2
SCR1
SCR0
÷
INTERRUPT REQUEST
TRANSMITTER CPU
4
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
SCALER
PRE-
DIVIDER
BAUD
PEN
PTY
Figure 13-5. ESCI Transmitter
TXINV
÷
GENERATION
16
PARITY
SCTE
SCTIE
TC
TCIE
T8
M
H
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
L
Freescale Semiconductor
Figure
SCI_TxD
13-4.