AT89C51CC03U-S3SIM ATMEL [ATMEL Corporation], AT89C51CC03U-S3SIM Datasheet - Page 103

• Manufacturer Part Number: AT89C51CC03U-S3SIM
• Description: Enhanced 8-bit MCU with CAN Controller and Flash Memory
• Manufacturer: ATMEL [ATMEL Corporation]

CAN Autobaud and
Listening Mode
Routines Examples
4182I–CAN–06/05
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
TxDC
RxDC
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