AT89C51CC03U-S3SIM ATMEL [ATMEL Corporation], AT89C51CC03U-S3SIM Datasheet - Page 102

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

Time Trigger
Communication (TTC)
and Message Stamping
Figure 55. Block Diagram of CAN Timer
102
AT89C51CC03
CLOCK
CANSTCH.4
CANSTCH.5
Fcan
RXOK i
TXOK i
CANSTMPH and CANSTMPL
÷ 6
The AT89C51CC03 has a programmable 16-bit Timer (CANTIMH and CANTIML) for
message stamp and TTC.
This CAN Timer starts after the CAN controller is enabled by the ENA bit in the CANG-
CON register.
Two modes in the timer are implemented:
•
Note:
•
The CAN Timer works in a roll-over from FFFFh to 0000h which serves as a time base.
When the timer roll-over from FFFFh to 0000h, an interrupt is generated if the ETIM bit
in the interrupt enable register IEN1 is set.
CANTCON
CANTIMH and CANTIML
Time Trigger Communication:
–
Message Stamping
–
–
–
–
Capture of this timer value in the CANTTCH and CANTTCL registers on
Start Of Frame (SOF) or End Of Frame (EOF), depending on the SYNCTTC
bit in the CANGCON register, when the network is configured in TTC by the
TTC bit in the CANGCON register.
In this mode, CAN only sends the frame once, even if an error occurs.
Capture of this timer value in the CANSTMPH and CANSTMPL registers of
the message object which received or sent the frame.
All messages can be stamps.
The stamping of a received frame occurs when the RxOk flag is set.
The stamping of a sent frame occurs when the TxOk flag is set.
CANGCON.1
CANTTCH and CANTTCL
ENA
When 0xFFFF to 0x0000
CANGCON.5
TTC
CANGCON.4
SYNCTTC
SOF on CAN frame
EOF on CAN frame
OVRTIM
CANGIT.5
4182I–CAN–06/05