User manual

UM0036 STice features
Doc ID 7705 Rev 11 261/385
wide. As a result, the read value may be 1, 2 or 3-bytes long. These data bytes are
constants or part of constants accessed by the program.
To simplify the data display, when data is read, the value of the data is shown only
when it is valid, that is one cycle after the data request was made (if there is no stall).
● R event (Read event): It is the type of read event. The following values can be
displayed:
– Data read
– Stack read
– Read stall
– DMA read
This field can be used to filter the disassembled trace records which are displayed.
● W addr (Write address): It is the 24-bit address of the data being written.
● W value (Write value): It is the contents of the 8-bit data write bus or the DMA write
bus. These data bytes are variables or part of variables written by the program.
● W event (Write event): It is the type of write event. The following values can be
displayed:
– Data write
– Stack write
– Write stall
– DMA write
This field can be used to filter the trace records which are displayed.
● Time (Timestamp): The value in nanoseconds of the time marker at this event. The
time stamp is not recalculated when you remove events from the display by filtering
(see Filter lines: Trace records can be filtered using the Trace Display Filter dialog box
(Figure 198). To open this window, select Filter Lines from the Trace window contextual
menu. The line filter is used to restrict the trace display to the operation that you are
interested in. Only the selected trace entries appear in the Trace window (all others are
hidden). The record number and timestamp are not recalculated when lines are
removed from the display.).
● Time event (timestamp event): Signals the occurrence of events that affect the validity
of the value in the Time column, in particular:
– Restart: An automatic restart of the 38-bit timestamp counter. This means that the
38-bit Timestamp counter has reached its maximum and has started counting
from 0 again, and the fact has been registered by the trace. Note that a trace
recording is forced each time a timestamp counter restart occurs. This allows you
to be able to calculate the absolute amount of time passed between the beginning
of the run and any given trace record. However, after a Restart message is shown,
remember that the value in the timestamp column is only relative to the last
Restart message, not absolute. To obtain the true value of time passed, it is
necessary to take into account all the restart events between two records. The
frequency of the time stamp counter is 100 Mhz. The counter overflows every
2
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that is around 46 minutes (45 minutes and 49 seconds).
– Discontinuity: Interruption of the timestamp counter's ability to write to the trace,
due to the emulator's processor being in energy-saving mode, such as after a halt
instruction. While the timestamp counter continues, there is no way to force the
trace to record any restart messages that occur when the counter restarts.
Because of this, there is no way to determine the time elapsed between two