8XC196L
X
SUPPLEMENT
iv
CHAPTER 6
SYNCHRONOUS SERIAL I/O PORT
6.1 SSIO 0 CLOCK REGISTER........................................................................................... 6-1
6.2 SSIO 1 CLOCK REGISTER........................................................................................... 6-2
CHAPTER 7
EVENT PROCESSOR ARRAY
7.1 EPA FUNCTIONAL OVERVIEW................................................................................... 7-1
7.1.1 EPA Mask Registers .................................................................................................7-4
7.1.2 EPA Pending Registers ............................................................................................7-5
7.1.3 EPA Interrupt Priority Vector Register .......................................................................7-6
CHAPTER 8
J1850 COMMUNICATIONS CONTROLLER
8.1 J1850 FUNCTIONAL OVERVIEW................................................................................. 8-1
8.2 J1850 CONTROLLER SIGNALS AND REGISTERS..................................................... 8-3
8.3 J1850 CONTROLLER OPERATION............................................................................. 8-4
8.3.1 Control State Machine ..............................................................................................8-4
8.3.1.1 Cyclic Redundancy Check Generator ..................................................................8-4
8.3.1.2 Bus Contention .....................................................................................................8-5
8.3.1.3 Bit Arbitration ........................................................................................................8-5
8.3.1.4 Error Detection .....................................................................................................8-5
8.3.2 Symbol Synchronization and Timing Circuitry ...........................................................8-5
8.3.2.1 Clock Prescaler ....................................................................................................8-6
8.3.2.2 Digital Filter ..........................................................................................................8-6
8.3.2.3 Delay Compensation ............................................................................................8-6
8.3.2.4 Symbol Encoding and Decoding ..........................................................................8-6
8.3.3 Bit Arbitration Example .............................................................................................8-7
8.4 MESSAGE FRAMES..................................................................................................... 8-8
8.4.1 Standard Messaging ................................................................................ ...... ...........8-9
8.4.1.1 Header .................................................................................................................8-9
8.4.1.2 CRC Byte .............................................................................................................8-9
8.4.1.3 Normalization Bit ..................................................................................................8-9
8.4.1.4 Start and End Message Frame Symbols ............................................................8-10
8.4.2 In-frame Response Messaging ...............................................................................8-12
8.4.2.1 IFR Messaging Type 1: Single Byte, Single Responder ....................................8-12
8.4.2.2 IFR Messaging Type 2: Single Byte, Multiple Responders ................................8-12
8.4.2.3 IFR Messaging Type 3: Multiple Bytes, Single Responder ................................8-13
8.5 TRANSMITTING AND RECEIVING MESSAGES....................................................... 8-13
8.5.1 Transmitting Messages ...........................................................................................8-13
8.5.2 Receiving Messages ...............................................................................................8-15
8.5.3 IFR Messages .........................................................................................................8-16