NXP Semiconductors MWCT101 S Series, Reference Manual

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Table 50-6. JTAG instructions (continued)
Instruction Code[3:0] Instruction summary
HIGHZ 1001 Selects bypass register while three-stating all output pins and
asserting functional reset
CLAMP 1100 Selects bypass register while applying preloaded values to
output pins and asserting functional reset
Arm_IDCODE 1110 Arm JTAG-DP Instruction
BYPASS 1111 Selects bypass register for data operations
Factory debug reserved 0101, 0110, 0111, 1101 Intended for factory debug only
Arm JTAG-DP Reserved 1000, 1010, 1011, 1110 These instructions will go the Arm JTAG-DP controller.
Please see the Arm JTAG-DP documentation for more
information on these instructions.
Reserved
2
All other opcodes Decoded to select bypass register
1. Device IDCODE can only be read in JTAG mode
2. The manufacturer reserves the right to change the decoding of reserved instruction codes in the future
50.6 MDM-AP status and control registers
Through the Arm Debug Access Port (DAP), the debugger has access to the status and
control elements, implemented as registers on the DAP bus as shown in
Figure 50-3 .
These registers provide additional control and status for low power mode recovery and
typical run-control scenarios. The status register bits also allow the debugger to get
updated status of the core without having to initiate a bus transaction across the crossbar
switch, thus remaining less intrusive during a debug session.
These DAP control and status registers are not memory mapped within the system
memory map and are only accessible via the DAP using JTAG or SWD. The MDM-AP is
accessible as Debug Access Port 1 with the available registers shown in the table below.
Table 50-7. MDM-AP register summary
Address Register Description
0x0100_0000 Status See MDM-AP Status Register
0x0100_0004 Control See MDM-AP Control Register
0x0100_00FC ID Read-only identification register that always reads as 0x001C_0000
MDM-AP status and control registers
MWCT101xS Series Reference Manual, Rev. 3, 07/2019
1718 NXP Semiconductors