Specifications
7
As of March 2011, TRACE32 trace information can
be streamed to a host hard-disk from the running
target. The large amount of program flow data
which can result from this method, leads to a sig-
nificant simplification of the code-coverage.
Trace-based Code-Coverage
Proof of statement coverage and condition coverage is
often required to meet system quality specifications in
industries such as medical and automotive.
•Statement coverage proves that each line of code
was executed during the system test.
• Condition coverage proves that for each condi-
tional instruction both pass and fail branches were
executed at least once.
For many embedded systems highly optimized code
must be tested in real-time. The alternatives of code
instrumentation and non-real-time operation cannot
be used in these cases.
To be able to meet these requirements, the target pro-
cessor/SoC must fulfill the following prerequisites:
1. The cores which are implemented must have a core
tracelogic(seegure8).Thislogicgeneratesinfor-
mation about the instructions executed by the core.
Depending on the operation of the trace logic, infor-
mation about the task switches and the read/write
operations can also appear.
2. The processor/SoC must have a trace port with suf-
ficient bandwidth so that the trace information can
be recorded by an external tool without any informa-
tion loss.
The Classic Measurement Process
Until now, code-coverage analysis was performed with
TRACE32 using the following steps:
1. Start program execution and automatically stop
when the trace memory is full.
2. Transfer the trace memory content to the code-
coverage database.
3. Continue program execution.
For each measurement step, the amount of data col-
lected was limited by the size of the memory available
within the trace tool. The results of the code-coverage-
analysis could be checked after the total measurement
was completed or, if needed, after each intermediate
step.
New: Streaming
If the trace data is transferred to a drive on the host
computer at the time of recording, the complete soft-
ware routine can be recorded in one measurement
step. The streamed data is stored within a file on the
hard-disk. To avoid completely filling the hard-disk with
trace data, TRACE32 stops streaming as soon as less
than 1 GByte of free memory remains.
To be able to stream, the following technical prerequi-
sites must be fulfilled:
• 64-bit host computer and 64-bit TRACE32 execut-
able
• Interface between trace tool and host computer
must be as fast as possible.
• Optimal conguration of the trace source and the
trace tool
TRACE32 PowerView
64-bit host
SoC
Trace port JTAG
Trace
control
logic
Trace memory
as FIFO
File on
hard-disk
Core
trace
logic
Core
Fig.8: Forthecode-coverageanalysis,upto1TByteoftracedatacanbestreamedtothehostcomputer.
Code-Coverage – Simplified