2.14. Constraints and limitations of use

Table 2.7 shows the trace packets that the STM does not generate, and the reason they are not generated.

Table 2.7. Non-generated trace packets

NameTypeDescription and reason for non-generation
M16MasterIdentifies the currently active master where the new master number differs from the old master number in bits [15:8]. The STM design has only 129 masters, 128 for software stimulus and 1 master for hardware stimulus, therefore the M8 packet is sufficient and the M16 packet is never required.
D64, D64TS, D64M, D64MTSDataThe STM does not generate 64-bit data packets.
TIME(_TS)TimeThe STM only uses global timestamps, so this packet provides no useful information.
NULL_TSFillerNULL packet with timestamp. NULL cannot be generated in response to stimulus so it is impossible to force a timestamp for NULL in the STM.
USER(_TS)UserConveys implementation-specific metadata to the trace receiver. The STM has no such information which is not already accessible through APB reads and therefore does not generate this packet type.
FREQ_TSTimestamp frequencyTimestamp clock frequency, timestamped. FREQ cannot be generated in response to stimulus so it is impossible to force a timestamp for FREQ in the STM.
XSYNC(_TS)Cross-synchronizationThe STM does not support cross-synchronization using XSYNC.

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