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Home > ETMv3 Signal Protocol > Data tracing > Value not traced packet |
Value not traced packets comprise a Value not traced header
byte, followed by an optional data address, as Figure 7.35 shows. The
decompression software must work backwards from the final data transfer, using
the Value not traced packets in combination with the Normal data
packets, to determine which of the LSM
values were
traced.
The data address is output if the address of the transfer
is noncontiguous relative to the previous transfer, so that the address
of subsequent data transfers in the LSM
can be
determined if they are traced. It therefore follows the same rules
as for Normal data packets. See The A bit for more information.
If an LSM
instruction is traced, instruction
tracing continues until the LSM
completes, even if TraceEnable is deasserted before the
LSM completes. This means that instructions executed under an LSM
are
also traced, regardless of whether TraceEnable remains
asserted. For more information, see Independent load/store unit.