AN2345 Freescale Semiconductor / Motorola, AN2345 Datasheet - Page 21

• Manufacturer Part Number: AN2345
• Description: Real-Time Memory Manager for StarCore DSPs
• Manufacturer: Freescale Semiconductor / Motorola

5
VSMM Benchmarking
The ExampleRTOS2 binary, ExampleRTOS2.eld, was built with the VSMM preprocessor macro
defined, so only VSMM is used for all memory allocations within the supplied executable. Download
ExampleRTOS2 without requiring a build, as follows:
1. Select Preferences from the Codewarrior IDE Edit menu.
2. From within the resulting window select Build Setting from under General.
3. Set the Build before running statement to Never.
4. Select OK to accept your changes and close this window.
5. Download the example by clicking on the Run Debug icon. Refer to Figure 11 on page 26 to learn the
This section describes the VSMM performance and memory requirements. Since the VSMM can be
tailored for a specific application, we used Metrowerks Codewarrior v2.02 Level 3 optimization to build a
simple application that exercises all VSMM functionality. Table 5 details the functionality exercised and
the associated cycle counts. The cycle counts were recorded via the MSC8101 EOnCE with the
application running on a Motorola MSC8101ADS board. The cycles reported for the VSMM in Table 5
are the results when the following are true:
• Argument verification is used
• gucVSMM_ARG_CHK_EN = 1
• Critical method 1, VSMM_CRITICAL_METHOD = 1
• The 20 cycles associated with the EOnCE overhead are included. These cycles are slightly higher if
Table 6 shows the VSMM code space requirements to achieve the tested functionalities. The recorded
numbers are from the resulting MAP file with Level 3optimization applied. The VSMM code space size
shown in Table 6 is with argument verification enabled and critical method 1 selected. The worst case
code space requirement occurs when critical method 2 is used, which increases the code space size by 32
bytes to a total of 1,460 bytes.
location of this icon.
critical method 2 or 3 is used, with critical method 2 resulting in the highest number of cycles. See
Table 9 for the total task cycle numbers with critical method 2 selected.
Memory initialization
Static heap creation
Dynamic heap creation
Dynamic heap destruction
Memory allocation
Memory free
Memory query
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Table 5. Memory Manager Task Cycles
VSMMMemInit
VSMMMemCreate
VSMMMemAllocCreate
VSMMMemDestroy
VSMMMemAlloc
VSMMMemFree
VSMMMemQuery
VSMM Function
VSMM Benchmarking
VSMM Cycles
147
220
159
30
71
68
68
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