MC68HC908AT32 Datasheet, PDF (251/378 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 23
MSCAN Controller
23.1 Introduction
The MSCAN08 is the specific implementation of the scalable controller area network (MSCAN) concept
targeted for the Freescale M68HC08 Microcontroller Family.
The module is a communication controller implementing the CAN2.0A/B protocol as defined in the
BOSCH specification dated September 1991.
The CAN protocol was primarily, but not exclusively, designed to be used as a vehicle serial data bus,
meeting the specific requirements of this field: real-time processing, reliable operation in the
electromagnetic interference (EMI) environment of a vehicle, cost-effectiveness, and required bandwidth.
MSCAN08 utilizes an advanced buffer arrangement, resulting in a predictable real-time behavior, and
simplifies the application software.
23.2 Features
Basic features of the MSCAN08 are:
• Modular architecture
• Implementation of the CAN protocol — Version 2.0A/B:
– Standard and extended data frames
– 0–8 bytes data length
– Programmable bit rate up to 1 Mbps depending on the actual bit timing and the clock jitter of
the phase-locked loop (PLL)
• Support for remote frames
• Double-buffered receive storage scheme
• Triple-buffered transmit storage scheme with internal prioritization using a “local priority” concept
• Flexible maskable identifier filter supports alternatively one full size extended identifier filter or two
16-bit filters or four 8-bit filters
• Programmable wakeup functionality with integrated low-pass filter
• Programmable loop-back mode supports self-test operation
• Separate signalling and interrupt capabilities for all CAN receiver and transmitter error states
(warning, error passive, bus-off)
• Programmable MSCAN08 clock source either cpu bus clock or crystal oscillator output
• Programmable link to on-chip timer interface module (TIMB) for time-stamping and network
synchronization
• Low-power sleep mode
MC68HC908AT32 Data Sheet, Rev. 3.1
Freescale Semiconductor
251