Freescale’s Scalable Controller Area Network (S12MSCANV3)
8.1.3
Features
The basic features of the MSCAN are as follows:
•
Implementation of the CAN protocol — Version 2.0A/B
— Standard and extended data frames
— Zero to eight bytes data length
— Programmable bit rate up to 1 Mbps
— Support for remote frames
1
•
•
•
Five receive buffers with FIFO storage scheme
Three transmit buffers with internal prioritization using a “local priority” concept
Flexible maskable identifier filter supports two full-size (32-bit) extended identifier filters, or four
16-bit filters, or eight 8-bit filters
•
•
•
•
•
Programmable wakeup functionality with integrated low-pass filter
Programmable loopback mode supports self-test operation
Programmable listen-only mode for monitoring of CAN bus
Programmable bus-off recovery functionality
Separate signalling and interrupt capabilities for all CAN receiver and transmitter error states
(warning, error passive, bus-off)
•
•
•
•
Programmable MSCAN clock source either bus clock or oscillator clock
Internal timer for time-stamping of received and transmitted messages
Three low-power modes: sleep, power down, and MSCAN enable
Global initialization of configuration registers
8.1.4
Modes of Operation
For a description of the specific MSCAN modes and the module operation related to the system operating
modes refer to Section 8.4.4, “Modes of Operation”.
8.2
External Signal Description
The MSCAN uses two external pins.
NOTE
On MCUs with an integrated CAN physical interface (transceiver) the
MSCAN interface is connected internally to the transceiver interface. In
these cases the external availability of signals TXCAN and RXCAN is
optional.
8.2.1
RXCAN — CAN Receiver Input Pin
RXCAN is the MSCAN receiver input pin.
1. Depending on the actual bit timing and the clock jitter of the PLL.
S12P-Family Reference Manual, Rev. 1.13
Freescale Semiconductor
253
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