s908ey8ad4cfjer Freescale Semiconductor, Inc, s908ey8ad4cfjer Datasheet - Page 127

• Manufacturer Part Number: s908ey8ad4cfjer
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

13.4 Functional Description
Figure 13-2
serial communication between the MCU and remote devices, including other MCUs. The transmitter and
receiver of the ESCI operate independently, although they use the same baud rate generator. During
normal operation, the CPU monitors the status of the ESCI, writes the data to be transmitted, and
processes received data.
The baud rate clock source for the ESCI can be selected via the configuration bit, ESCIBDSRC, of the
CONFIG2 register ($001E).
Freescale Semiconductor
CGMXCLK
BUS CLOCK
SL=1 -> SCI_CLK = BUSCLK
SL=0 -> SCI_CLK = CGMXCLK (4x BUSCLK)
RxD
shows the structure of the ESCI module. The ESCI allows full-duplex, asynchronous, NRZ
Enhanced
SCALER
SCRIE
SCTIE
PRE-
RWU
LINR
TCIE
SBK
ILIE
SL
TE
RE
SHIFT REGISTER
ESCI DATA
REGISTER
RECEIVE
÷ 4
CONTROL
WAKEUP
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
SCTE
SCRF
SCALER
Figure 13-2. ESCI Module Block Diagram
IDLE
TC
ENSCI
PRE-
GENERATOR
BAUD RATE
÷ 16
CONTROL
RECEIVE
INTERNAL BUS
LOOPS
BKF
RPF
DATA SELECTION
CONTROL
OR
NF
FE
PE
FLAG
CONTROL
WAKE
ILTY
PEN
LOOPS
PTY
ENSCI
M
TRANSMIT
CONTROL
SHIFT REGISTER
TXINV
ORIE
NEIE
FEIE
PEIE
R8
REGISTER
TRANSMIT
T8
ESCI DATA
Functional Description
BUS_CLK
SCI_TxD
ACLK bit in SCIACTL
ARBITER-
RxD
SL
127
TxD