Encore SIM EDITOR SOFTWARE Guide de l'utilisateur télécharger pdf (Page 94)

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Modeling Your Design

In simulations, this memory model used 4 MB of machine memory

with the /*sparse*/ pragma, 81 MB without it. There is a small

runtime performance cost to sparse memory models: the simulation

of the memory with the /*sparse*/ pragma took 64 seconds, 56

seconds without it.

The larger the memory, and the fewer elements in the memory that

your design reads or writes to, the more machine memory you will

save by using this feature. It is intended for memories that contain at

least a few MBs. If your design accesses 1% of its elements you could

save 97% of machine memory. If your design accesses 50% of its

elements, you save 25% of machine memory. Don’t use this feature

if your design accesses more than 50% of its elements because using

the feature in these cases may lead to more memory consumption

than not using it.

Using sparse memory models does not increase the memory size

limits described in the previous section.

Note:

• Sparse memory models cannot be manipulated by PLI

applications through tf calls (the tf_nodeinfo routine issues a

warning for sparse memory and returns NULL for the memory

handle).

• Sparse memory models cannot be used as a personality matrix

in PLA system tasks.

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Encore SIM EDITOR SOFTWARE Guide de l'utilisateur Page 94