Implicit DSP/BIOS Instrumentation
Instrumentation
3-29
3.6 Implicit DSP/BIOS Instrumentation
The instrumentation needed to allow the DSP/BIOS Analysis Tools to display
the raw logs, system statistics, and CPU load are built automatically into a
DSP/BIOS program to provide implicit instrumentation. You can enable
different components of DSP/BIOS implicit instrumentation by using the RTA
Control Panel Analysis Tool in Code Composer, as described in section
3.4.4.2,
Control of Implicit Instrumentation
, page 3-15.
DSP/BIOS instrumentation is efficient—when all implicit instrumentation is
enabled, the CPU load increases less than one percent for a typical
application. See section 3.4,
, page 3-15, for
details about instrumentation performance.
3.6.1
The CPU Load
The CPU load is defined as the percentage of instruction cycles that the CPU
spends doing application work. That is, the percentage of the total time that
the CPU is:
❏
Running hardware interrupts, software interrupts, tasks, or periodic
functions
❏
Performing I/O with the host
❏
Running any user routine
❏
In power-save or hardware idle mode (’C55x only)
When the CPU is not doing any of these, it is considered idle.
Although the CPU is idle during power-save mode, which is supported on
’C55x through the PWRM module, the DSP/BIOS idle loop cannot run. As a
result, the CPU load cannot be calculated and is shown as 100%.
To view the CPU Load tool, choose
Tools > RTA > CPU Load
from the
CCStudio menu bar.
All CPU activity is divided into work time and idle time. To measure the CPU
load over a time interval T, you need to know how much time during that
interval was spent doing application work (t
w
) and how much of it was idle
time (t
i
). From this you can calculate the CPU load as follows:
Since the CPU is always either doing work or in idle it is represented as
follows:
CPUload
t
w
T
-----
100
×
=
T
t
w
t
i
+
=
Summary of Contents for TMS320 Series
Page 1: ...TMS320 DSP BIOS v5 40 User s Guide Literature Number SPRU423G April 2009 ...
Page 16: ...xvi ...
Page 152: ...Tasks 4 48 Figure 4 12 Trace from Example 4 7 ...
Page 168: ...Semaphores 4 64 Figure 4 14 Trace Results from Example 4 11 ...
Page 202: ...5 20 ...
Page 287: ...Index 9 Index Void 1 11 W words data memory 3 15 of code 1 5 wrapper function 2 29 ...
Page 288: ...Index 10 Index ...