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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 993
UG585 (v1.11) September 27, 2016
Appendix B: Register Details
Register LAR Details
Register (ptm) LSR
Description Lock Access Register
Field Name Bits Type Reset Value Description
31:0 wo 0x0 Write Access Code.
Write behavior depends on PADDRDBG31 pin:
- PADDRDBG31=0 (lower 2GB):
After reset (via PRESETDBGn), PTM is locked,
i.e., writes to all other registers using lower 2GB
addresses are ignored.
To unlock, 0xC5ACCE55 must be written this
register.
After the required registers are written, to lock
again, write a value other than 0xC5ACCE55 to
this register.
- PADDRDBG31=1 (upper 2GB):
PTM is unlocked when upper 2GB addresses are
used to write to all the registers.
However, write to this register is ignored using a
upper 2GB address!
Note: read from this register always returns 0,
regardless of PADDRDBG31.
Name LSR
Relative Address 0x00000FB4
Absolute Address debug_cpu_ptm0: 0xF889CFB4
debug_cpu_ptm1: 0xF889DFB4
Width 3 bits
Access Type ro
Reset Value 0x00000003
Description Lock Status Register