Freescale Semiconductor MPC5553 - Configuring the NDI for Nexus Messaging

MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
Freescale Semiconductor 25-11
instruction opcode for each Nexus client is listed in Table 25-5. Opcodes for all other instructions
supported by Nexus clients can be found in the relevant sections of this chapter.
25.4.2 Configuring the NDI for Nexus Messaging
The NDI is placed in disabled mode upon exit of power-on reset. If message transmission via the auxiliary
port is desired, a write to the port configuration register (PCR) located in the NPC is then required to enable
the NDI and select the mode of operation. Asserting MCKO_EN in the PCR places the NDI in enabled
mode 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 to
the PCR, the PCR lsb must be written to a logic 0. Setting the lsb of the PCR enables factory debug mode
and prevents the transmission of Nexus messages.
Figure 25-6 describes the NDI configuration options.
Table 25-4. JTAG Client Select Instructions
JTAGC Instruction Opcode Description
ACCESS_AUX_TAP_NPC 10000 Enables access to the NPC TAP controller
ACCESS_AUX_TAP_ONCE 10001 Enables access to the e200z6 OnCE TAP controller
ACCESS_AUX_TAP_eTPU 10010 Enables access to the eTPU Nexus TAP controller
ACCESS_AUX_TAP_DMAN3 10011 Enables access to the eDMA Nexus TAP controller
Table 25-5. Nexus Client JTAG Instructions
Instruction Description Opcode
NPC JTAG Instruction Opcodes
NEXUS_ENABLE Opcode for NPC Nexus Enable instruction (4-bits) 0x0
BYPASS Opcode for the NPC BYPASS instruction (4-bits) 0xF
e200z6 OnCE JTAG Instruction Opcodes
1
1
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) 0x7C
BYPASS Opcode for the e200z6 OnCE BYPASS instruction (10-bits) 0x7F
NDEDI JTAG Instruction Opcodes
NEXUS_ENABLE Opcode for NDEDI Nexus Enable instruction (4-bits) 0x0
BYPASS Opcode for the NDEDI BYPASS instruction (4-bits) 0xF
eDMA Nexus JTAG Instruction Opcodes
NEXUS_ACCESS Opcode for eDMA Nexus Enable instruction (4-bits) 0x0
BYPASS Opcode for the eDMA Nexus BYPASS instruction (4-bits) 0xF