MC68HC908AT32 Datasheet, PDF (139/378 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 16
Serial Communications Interface Module (SCI)
16.1 Introduction
The serial communications interface (SCI) allows asynchronous communications with peripheral devices
and other microcontroller units (MCU).
16.2 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 central processor unit (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
16.3 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 16-1 shows the full names and the generic names of the
SCI I/O pins.The generic pin names appear in the text of this section.
MC68HC908AT32 Data Sheet, Rev. 3.1
Freescale Semiconductor
139