RM0017 Datasheet, PDF (796/904 Pages) STMicroelectronics – The SPC560Bx and SPC560Cx is a new family

RM0017
Nexus Development Interface (NDI)
Note:
On HALT or STOP mode exit, the MC_ME asserts the lp_mode_exit_req input after
ensuring that the regulator and memories are in normal mode and before the processor
exits its halted or stopped state. The mode transition will then not proceed until the
lp_mode_exit_ack output has been asserted. The MC_RGM asserts the exit_from_standby
input when executing a reset sequence due to a STANDBY exit. The reset sequence will
then not complete until the lp_mode_exit_ack output has been asserted.
The notification to the debugger of a low-power mode exit consists of driving the TDO pad to
`0'. The debugger acknowledges that the transition from a low-power mode can continue by
setting the low-power mode sync bit in the port control register (written by debugger), which
results in the assertion of the lp_sync_out input.
The debugger clock multiplexer may not guarantee glitch free switching. Therefore, TCK
should be disabled from when the debugger clears the sync bit in ENTRY_CLR until the
debugger senses the falling edge of TDO in TDO_SET.
33.7.2
Enabling Nexus Clients for TAP Access
After the conditions have been met to bring the NDI out of the reset state, the loading of a
specific instruction in the JTAG controller (JTAGC) block is required to grant the NDI
ownership of the TAP. Each Nexus client has its own JTAGC instruction opcode for
ownership of the TAP, granting that client the means to read/write its registers. The JTAGC
instruction opcode for each Nexus client is shown in Table 426. After the JTAGC opcode for
a client has been loaded, the client is enabled by loading its NEXUS-ENABLE instruction.
The NEXUS-ENABLE instruction opcode for each Nexus client is listed in Table 427.
Opcodes for all other instructions supported by Nexus clients can be found in the relevant
sections of this chapter.
Table 426. JTAGC Instruction Opcodes to Enable Nexus Clients
JTAGC Instruction
Opcode
Description
ACCESS_AUX_TAP_NPC
ACCESS_AUX_TAP_ONCE
10000 Enables access to the NPC TAP controller
10001 Enables access to the e200z0 TAP controller
Instruction
Table 427. Nexus Client JTAG Instructions
Description
NPC JTAG Instruction Opcodes
NEXUS_ENABLE
BYPASS
Opcode for NPC Nexus ENABLE instruction (4-bits)
Opcode for the NPC BYPASS instruction (4-bits)
e200z0 OnCE JTAG Instruction Opcodes⁽¹⁾
NEXUS2_ACCESS Opcode for e200z0 OnCE Nexus ENABLE instruction (10-bits)
BYPASS
Opcode for the e200z0 OnCE BYPASS instruction (10-bits)
1. Refer to the e200z0 reference manual for a complete list of available OnCE instructions.
Opcode
0x0
0xF
0x7C
0x7F
33.7.3
Configuring the NDI for Nexus Messaging
The NDI is placed in disabled mode upon exit of reset. If message transmission via the
auxiliary port is desired, a write to the port configuration register (PCR) located in the NPC
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