Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
394
MC9S12C-Family / MC9S12GC-Family
Freescale Semiconductor
Rev 01.24
13.4
Functional Description
This section provides a complete functional description of the SCI block, detailing the operation of the
design from the end user perspective in a number of subsections.
shows the structure of the SCI module. The SCI allows full duplex, asynchronous, NRZ serial
communication between the CPU and remote devices, including other CPUs. The SCI transmitter and
receiver operate independently, although they use the same baud rate generator. The CPU monitors the
status of the SCI, writes the data to be transmitted, and processes received data.
Figure 13-9. SCI Block Diagram
SCI DATA
RECEIVE
SHIFT REGISTER
SCI DATA
REGISTER
TRANSMIT
SHIFT REGISTER
REGISTER
BAUD RATE
GENERATOR
SBR12–SBR0
BUS
TRANSMIT
CONTROL
÷
16
RECEIVE
AND WAKEUP
DATA FORMAT
CONTROL
CONTROL
T8
PF
FE
NF
RDRF
IDLE
TIE
OR
TCIE
TDRE
TC
R8
RAF
LOOPS
RWU
RE
PE
ILT
PT
WAKE
M
CLOCK
ILIE
RIE
RXD
RSRC
SBK
LOOPS
TE
RSRC
TXD
RDRF/OR IRQ
TDRE IRQ
IDLE IRQ
TC IRQ
IRQ
TO CPU
Summary of Contents for MC9S12C Family
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