Chapter 15 Serial Communication Interface (S12MC9S12XDP512V5)
MC9S12XDP512 Data Sheet, Rev. 2.11
688 Freescale Semiconductor
15.4 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.

Figure 15-14 shows the structure of the SCI module. The SCI allows full duplex, asynchronous, 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 15-14. Detailed SCI Block Diagram

SCI Data
Receive
Shift Register
SCI Data
Register
Transmit
Shift Register
Register
Baud Rate
Generator
SBR12:SBR0
Bus
Transmit
Control
รท16
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
IREN
R16XCLK
Ir_RXD
TXD
Ir_TXD
R16XCLK
R32XCLK
TNP[1:0] IREN
Transmit
Encoder
Receive
Decoder
SCRXD
SCTXD
Infrared
Infrared
TC
TDRE
RDRF/OR
IDLE
Active Edge
Detect
Break Detect
RXD
BKDFE
BERRM[1:0]
BKDIE
BKDIF
RXEDGIE
RXEDGIF
BERRIE
BERRIF
SCI
Interrupt
Request
LIN Transmit
Collision
Detect