Rainbow Electronics ATmega64C1 - Manual (Page 185)

185
7647A–AVR–02/08
ATmega32/64/M1/C1
16.10 General CAN Registers
16.10.1 CAN General Control Register - CANGCON
• Bit 7 – ABRQ: Abort Request
This is not an auto resettable bit.
– 0 - no request.
– 1 - abort request: a reset of CANEN1 and CANEN2 registers is done. The pending
communications are immediately disabled and the on-going one will be normally
terminated, setting the appropriate status flags.
Note that CANCDMOB register remain unchanged.
• Bit 6 – OVRQ: Overload Frame Request
This is not an auto resettable bit.
– 0 - no request.
– 1 - overload frame request: send an overload frame after the next received frame.
The overload frame can be traced observing OVFG in CANGSTA register (c.f. Figure 16-9 on
page 176 ).
• Bit 5 – TTC: Time Trigger Communication
– 0 - no TTC.
– 1 - TTC mode.
• Bit 4 – SYNTTC: Synchronization of TTC
This bit is only used in TTC mode.
– 0 - the TTC timer is caught on SOF.
– 1 - the TTC timer is caught on the last bit of the EOF.
• Bit 3 – LISTEN: Listening Mode
– 0 - no listening mode.
– 1 - listening mode.
• Bit 2 – TEST: Test Mode
– 0 - no test mode
– 1 - test mode: intend for factory testing and not for customer use.
Note: CAN may malfunction if this bit is set.
• Bit 1 – ENA/STB: Enable / Standby Mode
Because this bit is a command and is not immediately effective, the ENFG bit in CANGSTA reg-
ister gives the true state of the chosen mode.
Bit 7 6 5 4 3 2 1 0
ABRQ OVRQ TTC SYNTTC LISTEN TEST ENA/STB SWRES CANGCON
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0