Page Comparison

Field

Definition

Unit

Total ticks per block process available

Measurement from the end of the CPU first interrupt, to the end of the next CPU interrupt (i.e., how many clock cycles have elapsed on the processor). This is a rough indication of how many clock cycles are available for processing. (You will not be able to utilize 100% of cycles because the audio interrupt handle requires some processing.) 

This is an especially important number to check when you are bringing up new hardware. The value shown here should be close to:

(Processor Speed) x (Block Size of Processing) / (Sample Rate)

If this doesn’t match, then there could be a mismatch in your processor speed, the audio sample rate, or the underlying “fundamental block size” of your implementation.

Lastly, there are two separate line items for ‘Total ticks per block process available’.

• Calculated: Manually calculated based on the processor clock speed and the block size and sample rate of the layout

• Measured: Processor clock ticks measured between blocks, based on the calling rate of the audio pump

Both of these units should nearly match, however be aware that if there are CPU overflows (>100% processing load), the ‘Measured’ metric may be increased/doubled because the audio pump was not completed during the current block.

CPU clock cycles

Average ticks per block used

Average of CPU clock cycles per block of audio data (10x)

CPU clock cycles

Instantaneous ticks per block used

CPU clock cycles required to process the last block of audio. This is the instantaneous measurement without smoothing. This number will change every time you profile.

CPU clock cycles

Peak ticks per block used

Peak instantaneous CPU clock cycles consumed when processing a block of audio data. This is a “sticky measurement” and shows the peak value since system startup. If you reprofile, then it will reset this value.

CPU clock cycles

Fast Heap

Memory usage from the memory allocated in the Fast Heap

Words

Fast Heap B

Memory usage from the memory allocated in the Fast Heap B

Words

Slow Heap

Memory usage from the memory allocated in the Slow Heap

Words

Total Memory

Fast Heap + Fast Heap B + Slow Heap

Words

Shared Heap

Memory usage from the allocated Shared Heap

Words

Heaps

At initialization time, memory to be used by the AWE Core instance for signal processing is allocated. The AWE Core refers to this memory as the heap. By default, AWE Core supports three heaps for which the BSP is responsible for allocating storage. Most commonly, heaps are allocated statically as large arrays. The heaps are:

• FASTA: storage accessible using the least time

• FASTB: a secondary bank of fast storage. Useful for memory that can be concurrently accessed with FASTA heaps

• SLOW: storage usually external and so more slowly accessed

• SHARED: Storage shared by and accessible to multiple Audio Weaver instances, used for multi-instance or IPC communication

To calculate Memory in MB: ((Total Heap Memory) * 4)/1000000