at89c51cc03c-slsim ATMEL Corporation, at89c51cc03c-slsim Datasheet - Page 102

• Manufacturer Part Number: at89c51cc03c-slsim
• Description: At89c51cc03 Enhanced 8-bit Mcu With Can Controller And Flash Memory
• Manufacturer: ATMEL Corporation

CAN Autobaud and
Listening Mode
Routines Examples
102
AT89C51CC03
To activate the Autobaud feature, the AUTOBAUD bit in the CANGCON register must
be set. In this mode, the CAN controller is only listening to the line without acknowledg-
ing the received messages. It cannot send any message. The error flags are updated.
The bit timing can be adjusted until no error occurs (good configuration find).
In this mode, the error counters are frozen.
To go back to the standard mode, the AUTOBAUD bit must be cleared.
Figure 56. Autobaud Mode
1. Init of CAN macro
// Reset the CAN macro
// Disable CAN interrupts
// Init the Mailbox
{
}
// Configure the bit timing
CANGCON = 01h;
ECAN = 0;
ETIM = 0;
for num_page =0; num_page <15; num_page++
CANBT1 = xxh
CANBT2 = xxh
CANBT3 = xxh
CANPAGE = num_channel << 4;
CANCONCH = 00h
CANSTCH = 00h;
CANIDT1 = 00h;
CANIDT2 = 00h;
CANIDT3 = 00h;
CANIDT4 = 00h;
CANIDM1 = 00h;
CANIDM2 = 00h;
CANIDM3 = 00h;
CANIDM4 = 00h;
for num_data =0; num_data <8; num_data++)
{
CANMSG = 00h;
CANGCON.3
AUTOBAUD
RxDC’
TxDC’
}
1
0
4182N–CAN–03/08
TxDC
RxDC