Freescale Semiconductor MPC5200B - Manual (Page 641)

MPC5200B Users Guide, Rev. 1
19-2 Freescale Semiconductor
Features
19.2 Features
The basic features of the MSCAN are as follows:
• 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 PLL)
— Support for remote frames
— 4 receive buffers with FIFO storage scheme
• 3 transmit buffers with internal prioritization using a “local priority” concept
• Flexible maskable identifier filter supports two full size extended identifier filters (two 32-bit) or four 16-bit filters or eight 8-bit
filters
• Programmable wake-up functionality
• Programmable loop back mode supports self-test operation
• Programmable listen-only mode for monitoring of CAN bus
• Separate signalling and interrupt capabilities for all CAN receiver and transmitter error states (Warning, Error Passive, Bus-Off)
• Programmable MSCAN clock source either IP bus clock or Oscillator clock
• Internal timer for time-stamping of received and transmitted messages
• Three low power modes: Sleep, Power Down and MSCAN Disabled
• Global initialization of configuration registers
19.3 External Signals
The MSCAN uses two external pins. In the MPC5200B the MSCAN pins are shared with other funtionality and can be available at two
different groups of pins. The configuration of the pin-muxing is controlled by the Port Configuration Register, see Section 7.
19.3.1 RXCAN — CAN Receiver Input Pin
RXCAN is the MSCAN receiver input pin.
19.3.2 TXCAN — CAN Transmitter Output Pin
TXCAN is the MSCAN transmitter output pin. The TXCAN output pin represents the logic level on the CAN bus:
0 = Dominant state
1 = Recessive state
19.4 CAN System
A typical CAN system with MSCAN is shown in Figure 19-2 . Each CAN station is connected physically to the CAN bus lines through a
transceiver chip. The transceiver is capable of driving the large current needed for the CAN bus and has current protection against defected
CAN or defected stations.