Datasheet

Chapter 13 Serial Communications Interface (S12SCIV2) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 385
Rev 01.24
13.1.4 Block Diagram
Figure 13-1 is a high level block diagram of the SCI module, showing the interaction of various functional
blocks.
Figure 13-1. SCI Block Diagram
13.2 External Signal Description
The SCI module has a total of two external pins:
13.2.1 TXD-SCI Transmit Pin
This pin serves as transmit data output of SCI.
13.2.2 RXD-SCI Receive Pin
This pin serves as receive data input of the SCI.
SCI DATA REGISTER
RECEIVE SHIFT REGISTER
RECEIVE & WAKE UP CONTROL
DATA FORMAT CONTROL
TRANSMIT CONTROL
TRANSMIT SHIFT REGISTER
SCI DATA REGISTER
BAUD
GENERATOR
RX DATA IN
÷16
BUS CLOCK
TXDATA OUT
IDLE IRQ
RDR/OR IRQ
TDRE IRQ
TC IRQ
ORING
IRQ GENERATION IRQ GENERATION
IRQ
TO CPU