Bus State Analysis
Operating the Bus Analyzer
MMDS0508OM/D
MOTOROLA
Bus State Analysis
87
If you select
Programmable, you must enter a frequency in the range of
50 Hz to 50 kHz, as the pop-up window requests. The MMDS will provide
a frequency close to the desired frequency and display it to the screen.
For example, entering 1000 will result in a timetag frequency of 1024 Hz.
If you select
Emulator, the system uses the MCU’s bus clock. In effect,
this stores the number of bus cycles.
Another setup option is specifying whether to store high-order time tag
bits (increasing the time tag from 16 to 24 bits) or data from the pod B
logic clips. To do so, enter the set multiplexer (SXB) command with the
appropriate tags or clips parameter value. (The default is clips.)
Collecting
Bus Data
To begin data collection, enter the ARM command, which arms the bus
state analyzer. The BSA status changes to
Armed
. The bus state
analyzer mode appears on the status line.
Next, enter the GO command, which starts program execution. The
MCU status changes to
Running
. If you are in a sequential mode, you
may be able to follow the occurrence of events from the highlighting
changes. (Such highlighting changes may be too fast to be helpful.) Data
collection continues through the specified number of counted events or
post-trigger cycles, or until code execution stops.
NOTE:
The GO command is not the only program-execution command that
works with the bus state analyzer. Alternative commands are: G, GOTIL,
STEP, STEPFOR, STEPTIL, and T.
If you enter either trace command (STEP or T) without a parameter
value when the bus state analyzer is armed, the analyzer trace window
appears over the debug screen. This temporary window shows the
cycles of the instruction just traced.
To manually halt data collection, enter the DARM or STOP command.
Entering the DARM command disarms the analyzer; the analyzer state
changes to
Disarmed
. (The DARM command does not stop emulation.)
Entering the STOP command stops data collection and emulation.
When data collection stops, you are ready to look at the data, per
Viewing Data
.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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