Example program provided by Embedded Systems Academy, Copyright 2000
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This example: CAN - name of application: can.c
====================================================
Demonstration of using the XA-C3 CAN Controller. The Self-test feature is used so only one development board is required.


Hardware requirements
=====================
Phytec RDK XAC3 with Philips XAC3


Software requirements
=====================
Phytec Flash Tools
  www.phytec.com
Raisonance XA compiler system - EVAL version sufficient
  www.raisonance.com
Optional: Development Assistant-C by RistanCASE
  www.ristancase.ch


Application description
=============================================
Demonstrates the use of the CAN Controller for transmitting and receiving.
Transmits a standard format message with ID 100H every time a switch is pressed or
released, the data byte corresponding to the switch state. 00H = no switches
pressed, 01H = switch S1 pressed, 02H = switch S2 pressed, 03H = both switches
S1 and S2 pressed
Messages received with the message ID 100H turn on or off LEDs D1 and D2 depending on
the data byte. 00H = both LEDs off, 01H = only LED D1 on, 02H = only LED D2 on,
03H = both LEDs D1 and D2 on.
The self test mode is enabled, so pressing the switches lights the LEDs.
Uses a CAN bus speed of 125kbps, with CIA settings.
Modifications:

To enable the CAN controller without self test mode change the line:
  CANCMR = 0x40;
to:
  CANCMR = 0x00;

To change the transmitted message ID to 101H change the line:
  msg_object_reg[0].MIDH = 0x100 << 5;
to:
  msg_object_reg[0].MIDH = 0x101 << 5;

To allow messages with ID in the range 100H -> 107H change the line:
  msg_object_reg[1].MSKH = 0x001f;
to:
  msg_object_reg[1].MSKH = 0x00ff;

To transmit 2 bytes change the line:
  msg_object_reg[0].MSKH = 0x0001;
to:
  msg_object_reg[0].MSKH = 0x0002;

and store the additional byte in tx_buffer[1] 

Data Space Memory Map:
011010H - 01101FH -> receive buffer
011000H - 01100FH -> transmit buffer
010000H - 010FFFH -> Memory Mapped Registers
000000H - 0003FFH -> application variables and stack