CANBus Control Area Network (Module P6, PA)68C3 Operations Manual North Atlantic Industries, Inc. 12/19/2014Rev: 2014-12-19-0947 www.naii.com Page 76 of 330Acceptance Mask LO (set per channel) (P6 – CAN A/B Only)Register contains the lower 16 bits of an acceptance mask for a 29-bit identifier.Register D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FUNCTIONAC_MSK_LO D D D D D D D D D D D D D D D D D=DATA BITFor CAN-A Messages (11-bit Identifiers)D15-D0: Unused.For CAN-B Messages (29-bit Identifiers)D15-D0: The least significant 16 bits of a 29-bit Identifier.0=The corresponding bit in the Acceptance Code Register cannot inhibit the match in the acceptance filtering.1=The corresponding bit in the Acceptance Code Register is used for acceptance filteringAcceptance Code HI (set per channel) (P6 – CAN A/B Only)Register contains the Acceptance Code; upper 11-bits for CAN-A, upper 16 bits for CAN-B.Register D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FUNCTIONAC_COD_HI X X X X D D D D D D D D D D D D D=DATA BITFor CAN-A Messages (11-bit code)D15-D13: UnusedD12-D2: 11-bit code.The MSB of the code is D12.D1-D0: UnusedFor CAN-B Messages (29-bit code)D15-D13: Unused.D12-D0: The thirteen most significant pits of a 29-bit code. The MSB of the code is D12.Acceptance Code LO (set per channel) (P6 – CAN A/B Only)Register contains the lower 16 bits of a 29-bit acceptance code.Register D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FUNCTIONAC_COD_LO D D D D D D D D D D D D D D D D D=DATA BITFor CAN-A Messages (11-bit Identifiers)D15-D0: Unused.For CAN-B Messages (29-bit Identifiers)D15-D0: The least significant 16 bits of a 29-bit code.FIFO Frame Components (P6 – CAN A/B Only)When an Interface Slot is configured to receive and a message comes in, a message will be loaded into theIFx_FIFO. The message will be constructed as follows:MSG_ID4 MSG_ID3 MSG_ID2 MSG_ID1 Data Size Data1 ... Data8MSG_ID4The upper 5 bits of the Message ID.Description D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FUNCTIONMSG_ID4 1 0 D x x x x x x x x D D D D D D=DATA BITD15: Start of Message Flag. Always equals 1 because this is the beginning of a message.D14: End of Message Flag. Always equals 0.D13: Message Identifier type. Equals 1 if message type is Can A. Equals 0 if message is Can B.For CAN-A Messages (11-bit Identifiers)D13-D5: Unused.
