5.4. Pipeline status and trace packet association in ETMv1

Table 5.2 shows the various trace packets that can be associated with different types of pipeline status.

Table 5.2. PIPESTAT and TRACEPKT association

Pipeline status

Associated trace packets

IE (Instruction Executed)

No packets.

ID (Instruction Executed with Data)

Data value only. 1 packet for bytes, 2 packets for halfwords, 4 packets for word transfers. n * 4 packets for load/store multiple operations, where n is the number of registers transferred.

ID (Instruction Executed with Data)

Address only. 1-5 packets containing the address of the transfer. For load/store multiples this is the address of the first transfer in the sequence.

ID (Instruction Executed with Data)

Data value and address. A number of packets for address followed by a number of packets for data. The address packets are the same as for ID, address only. The Data packets are the same as for ID, data value only.

IN (Instruction Not Executed)

No packets.

WT (Wait)

No packets.

BE (Branch Executed)

1-9[a] packets containing the branch destination. The most significant bit of each packet, bit [7], indicates if an additional packet is to follow. When bit [7] is HIGH there is an additional packet, when bit [7] is LOW it is the last packet. For a 5-packet branch destination, bits [6:4] of the final packet are used to indicate the reason for the branch address, for example a trace discontinuity.

BD (Branch Executed with Data)

A number of packets providing the information on the data access, followed by 1-9[a] packets containing the branch destination. The packets holding information on the data access are the same as those described in the ID entries in this table.

TR (Trigger)

The TRACEPKT[2:0] pins are used to output the pipeline status that is generated.

TD (Trace Disabled)

No packets. TRACEPKT[0] is used to indicate the status of TraceEnable when cycle-accurate tracing is enabled.

[a] 1-5 packets of address plus (for ETMv1.2 or later only) 1- 4 packets of Context ID.


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