Datasheet

MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
Freescale Semiconductor 177
Chapter 18
Serial Communications Interface (SCI)
18.1 Introduction
The SCI allows asynchronous communications with peripheral devices and other MCUs.
18.2 Features
The SCI module’s features include:
• Full Duplex Operation
• Standard Mark/Space Non-Return-to-Zero (NRZ) Format
• 32 Programmable Baud Rates
• Programmable 8-Bit or 9-Bit Character Length
• Separately Enabled Transmitter and Receiver
• Separate Receiver and Transmitter CPU Interrupt Requests
• Programmable Transmitter Output Polarity
• Two Receiver Wakeup Methods:
– Idle Line Wakeup
– Address Mark Wakeup
• Interrupt-Driven Operation with Eight Interrupt Flags:
– Transmitter Empty
–Transmission Complete
– Receiver Full
– Idle Receiver Input
– Receiver Overrun
– Noise Error
– Framing Error
– Parity Error
• Receiver Framing Error Detection
• Hardware Parity Checking
• 1/16 Bit-Time Noise Detection
18.3 Pin Name Conventions
The generic names of the SCI input/output (I/O) pins are:
• RxD (receive data)
• TxD (transmit data)
SCI I/O lines are implemented by sharing parallel I/O port pins. The full name of an SCI input or output
reflects the name of the shared port pin. Table 18-1 shows the full names and the generic names of the
SCI I/O pins.The generic pin names appear in the text of this subsection.