Intel 8XC196NT User Manual

Page of 155
7-13
CAN SERIAL COMMUNICATIONS CONTROLLER
7.4
CONFIGURING THE CAN CONTROLLER
This section explains how to configure the CAN controller. Several registers combine to control
the configuration: the CAN control register, the two bit timing registers, and the three mask reg-
isters. 
7.4.1
Programming the CAN Control (CAN_CON) Register 
The CAN control register (Figure 7-6) controls write access to the bit timing registers, enables
and disables global interrupt sources (error, status change, and individual message object), and
controls access to the CAN bus.
CAN_CON  
(87C196CB)
Address:
Reset State:
1E00H
01H
Program the CAN control (CAN_CON) register to control write access to the bit timing registers, to 
enable and disable CAN interrupts, and to control access to the CAN bus.
7
0
87C196CB
CCE
EIE
SIE
IE
INIT
Bit
Number
Bit
Mnemonic
Function
7
Reserved; for compatibility with future devices, write zero to this bit.
6
CCE
Change Configuration Enable
This bit controls whether software can write to the bit timing registers.
0 = prohibit write access 
1 = allow write access 
5:4
Reserved; for compatibility with future devices, write zeros to these bits.
3
EIE
Error Interrupt Enable
This bit enables and disables the bus-off and warn interrupts.
0 = disable bus-off and warn interrupts 
1 = enable bus-off and warn interrupts 
2
SIE
Status-change Interrupt Enable
This bit enables and disables the successful reception (RXOK), successful 
transmission (TXOK), and error code change (LEC2:0) interrupts.
0 = disable status-change interrupt 
1 = enable status-change interrupt 
When the SIE bit is set, the CAN controller generates a successful 
reception (RXOK) interrupt request each time it receives a valid message, 
even if no message object accepts it.
Figure 7-6.  CAN Control (CAN_CON) Register