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 83 of 330Therefore, for 1 MHz baud rate, the prescaler and time segment timing register bits should be set as follows:PRESCALER = 0TSEG1 = 3TSEG2 = 2Note: The sample point can be ‘moved/adjusted’ for system(s) known to have a long rise time or propagation delay.However, the relationship 5(quantum) = TSeg1 + TSeg2 must be maintained.Ch X Baud Rate Prescaler Extension Reg (Global)Configuration for baud prescaler. Writing to this register will not have any effect until D15 of Ch X Baud / BitTiming Register is set.Register D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FUNCTIONBaud Prescaler 0 0 0 0 0 0 0 0 0 0 0 0 D D D D D=DATA BITD3:0 BRPE: Baud Rate Prescaler Extension. 0x00-0x0F are valid values. By programming BRPE the Baud Rate Prescalercan be extended to values up to 1023. The actual interpretation by the hardware is that one more than the valueprogrammed by BRPE (MSBs) and BRP (LSBs) is used.Ch X TX/RX Error Counter (Global)Transmit and receive errors detected at the physical layer.Register D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FUNCTIONTX/RX ErrorCounter D D D D D D D D D D D D D D D D D=DATA BITD15 RP: Receive Error Passive0= The Receive Error Counter is below the error passive level.1= The Receive Error Counter has reached the error passive level as defined in the CAN Specification.D14:D8 REC6-0: Receive Error Counter. Actual state of Receive Error Counter. Values between 0 & 127.D7:D0 TEC7-0: Transmit Error Counter. Actual state of Transmit Error Counter. Values between 0 & 255.Level Control (Global)(Factory Use Only – For REFERENCE ONLY)Put device in diagnostic mode and transmit a constant dominant. Setting a “1” will cause the drivers to pulse adominant for at least 300 μs. The duration of the pulse is limited by the Dominant Time-Out feature of thetransceiver. The spec for the time-out states Minimum:300 μs, Typical:400 μs, Maximum: 700 μs.Register D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FUNCTIONTX/RX ErrorCounter 0 0 0 0 0 0 0 0 0 0 0 0 D D D D D=DATA BITD1: Channel 1D2: Channel 2D3: Channel 3D4: Channel 4All transmit and receive activity is stopped in diagnostic mode. The unit stays in this mode until a “0” is written.FIFO Frame (Global)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:PGN_HI PGN_LO SourceAddrDest. AddrOr PriorityData Size Data1 ... Data250
