NexusMPC5566 Microcontroller Reference Manual, Rev. 2Freescale Semiconductor 25-1125.4.2 Configuring the NDI for Nexus MessagingThe NDI is placed in disabled mode upon exit of power-on reset. If message transmission via the auxiliaryport is desired, a write to the port configuration register (PCR) located in the NPC is then required to enablethe NDI and select the mode of operation. Asserting MCKO_EN in the PCR places the NDI in enabledmode and enables MCKO. The frequency of MCKO is selected by writing the MCKO_DIV field.Asserting or negating the FPM bit selects full-port or reduced-port mode, respectively. When writing tothe PCR, the PCR lsb (least significant bit) must be written to a logic 0. Setting the lsb of the PCR enablesfactory debug mode and prevents the transmission of Nexus messages.Table 25-6 describes the NDI configuration options.Table 25-4. JTAG Client Select InstructionsJTAGC Instruction Opcode DescriptionACCESS_AUX_TAP_NPC 10000 Enables access to the NPC TAP controllerACCESS_AUX_TAP_ONCE 10001 Enables access to the e200z6 OnCE TAP controllerACCESS_AUX_TAP_eTPU 10010 Enables access to the eTPU Nexus TAP controllerACCESS_AUX_TAP_DMA 10011 Enables access to the eDMA Nexus TAP controllerTable 25-5. Nexus Client JTAG InstructionsInstruction Description OpcodeNPC JTAG Instruction OpcodesNEXUS_ENABLE Opcode for NPC Nexus Enable instruction (4-bits) 0x0BYPASS Opcode for the NPC BYPASS instruction (4-bits) 0xFe200z6 OnCE JTAG Instruction Opcodes11 Refer to the e200z6 Reference Manual for a complete list of available OnCE instructions.NEXUS3_ACCESS Opcode for e200z6 OnCE Nexus Enable instruction (10-bits) 0x7CBYPASS Opcode for the e200z6 OnCE BYPASS instruction (10-bits) 0x7FeDMA Nexus JTAG Instruction OpcodesNEXUS_ACCESS Opcode for eDMA Nexus Enable instruction (4-bits) 0x0BYPASS Opcode for the eDMA Nexus BYPASS instruction (4-bits) 0xFTable 25-6. NDI Configuration OptionsJCOMPAssertedMCKO_EN bit of the PortConfiguration RegisterFPM bit of the PortConfiguration Register ConfigurationNo X X ResetYes 0 X DisabledYes 1 1 Full-port modeYes 1 0 Reduced-port mode
