MC68HC908QC16_07 Datasheet, PDF (125/274 Pages) Freescale Semiconductor, Inc – Microcontrollers

Functional Description
13.3 Functional Description
shows the structure of the ESCI module. The ESCI allows full-duplex, asynchronous, NRZ 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.
INTERNAL BUS
BUS
CLOCK
BUSCLKX4
ESCI DATA
REGISTER
RxD
RECEIVE
SHIFT REGISTER
ESCI DATA
REGISTER
RxD
SCI_TxD
TRANSMIT
TxD
SHIFT REGISTER
LINR
SCTIE
TCIE
SCRIE
ILIE
TE
RE
RWU
SBK
ENHANCED
PRESCALER
SL
TXINV ^{BUS CLOCK}
R8
SL
T8
SCTE
TC
SCRF
IDLE
OR
NF
FE
PE
LOOPS
LOOPS
ENSCI
ORIE
NEIE
FEIE
PEIE
WAKEUP
CONTROL
RECEIVE
CONTROL
FLAG
CONTROL
TRANSMIT
CONTROL
BKF
ENSCI
RPF
÷4
PRE- BAUD RATE
SCALER GENERATOR
M
LINT
WAKE
ILTY
PEN
PTY
ACLK BIT
IN SCIACTL
÷ 16
DATA SELECTION
CONTROL
SL = 1 -> SCI_CLK = BUSCLK
SL = 0 -> SCI_CLK = BUSCLKX4
Figure 13-2. ESCI Module Block Diagram
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 3
Freescale Semiconductor
125