Freescale Semiconductor Starter Kit for MC9S12G TRK-USB-S12G128 TRK-USB-S12G128 Ficha De Dados
Códigos do produto
TRK-USB-S12G128
Serial Communication Interface (S12SCIV5)
MC9S12G Family Reference Manual, Rev.1.23
Freescale Semiconductor
669
20.1.4
Block Diagram
is a high level block diagram of the SCI module, showing the interaction of various function
blocks.
Figure 20-1. SCI Block Diagram
20.2
External Signal Description
The SCI module has a total of two external pins.
20.2.1
TXD — Transmit Pin
The TXD pin transmits SCI (standard or infrared) data. It will idle high in either mode and is high
impedance anytime the transmitter is disabled.
impedance anytime the transmitter is disabled.
20.2.2
RXD — Receive Pin
The RXD pin receives SCI (standard or infrared) data. An idle line is detected as a line high. This input is
ignored when the receiver is disabled and should be terminated to a known voltage.
ignored when the receiver is disabled and should be terminated to a known voltage.
20.3
Memory Map and Register Definition
This section provides a detailed description of all the SCI registers.
SCI Data Register
RXD Data In
Data Out TXD
Receive Shift Register
Infrared
Decoder
Receive & Wakeup
Control
Data Format Control
Transmit Control
Baud Rate
Generator
Bus Clock
1/16
Transmit Shift Register
SCI Data Register
Receive
Interrupt
Generation
Transmit
Interrupt
Interrupt
Generation
Infrared
Encoder
IDLE
RDRF/OR
TC
TDRE
BRKD
BERR
RXEDG
SCI
Interrupt
Request
Request