MC68HC55 Datasheet, PDF (2/40 Pages) Freescale Semiconductor, Inc – Two-Channel CMOS ASIC Device

MC68HC55 Technical Data
Section 1. DSI/D (Distributed System Interface – Digital)
The distributed system interface uses a 2-wire bus to interconnect a
master controller with sensors and firing units in an airbag system or
other automotive body control applications. Remote units are a key
feature of this system because they do not require a crystal or other
critical timing reference components which might be damaged in a
crash.
This document describes a 2-channel CMOS (complmenetary
metal-oxide semiconductor) ASIC (application-specific integrated
circuit) device, the MC68HC55. It communicates with the (master) serial
peripheral interface (SPI) from an MCU and generates interface signals
to/from an analog SmartMOS™ device called the DSI/P (where P
indicates the physical layer of the DSI system). 1.2 General Description
of the DSI System gives a general overview of the distributed system
interface (DSI), providing a context for understanding the details of this
specification.
1.1 Features
Technical Data
2
Features of the MC68HC55 include:
• Compact 16-pin narrow body SOIC (small outline integrated
circuit) package
• Compatible with Freescale SPI (serial peripheral interface)
communication interface
• Compatible with DSI/P analog ASIC
• Two independent DSI channels
• Pin assignments match DSI/P for easy connection
• Automatic CRC (cyclical redundancy check) generation and
checking for robust message verification
• 4-stage transmit and receive FIFOs (first in, first out)
• 8-bit or 16-bit messages, plus 4-bit CRC
SmartMOS is a trademark of Freescale Semiconductor, Inc.
MC68HC55
DSI/D (Distributed System Interface – Digital)