MC68HC812A4 Datasheet, PDF (224/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Serial Communications Interface Module (SCI)
14.8 External Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . .258
14.8.1 TXD Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .258
14.8.2 RXD Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .258
14.9 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259
14.10 Low-Power Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259
14.10.1 Run Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259
14.10.2 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259
14.10.3 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259
14.11 Interrupt Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .260
14.12 General-Purpose I/O Ports . . . . . . . . . . . . . . . . . . . . . . . . . . .260
14.13 Serial Character Transmission using the SCI. . . . . . . . . . . . .260
14.13.1 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .260
14.13.2 Code Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .261
14.2 Introduction
The serial communications interface (SCI) allows asynchronous serial
communications with peripheral devices and other MCUs.
14.3 Features
Features of the SCI include:
• Full-duplex operation
• Standard mark/space non-return-to-zero (NRZ) format
• 13-bit baud rate selection
• Programmable 8-bit or 9-bit data format
• Separately enabled transmitter and receiver
• Separate receiver and transmitter interrupt requests
• Two receiver wakeup methods:
– Idle line wakeup
– Address mark wakeup
MC68HC812A4 — Rev. 3.0
224
Serial Communications Interface Module (SCI)
Advance Information
MOTOROLA