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RAM Mapping Comparison for MATLAB Code

hdl.RAM, dsp.Delay, persistent array variables, and user-defined System object™ private properties can map to RAM, but have different attributes. The following table summarizes the differences.

Attributehdl.RAMdsp.Delay Persistent Arrays and
User-Defined System object Properties
RAM mapping criteriaUnconditionally maps to RAMMaps to RAM in HDL code under specific conditions. See RAM Mapping Requirements for dsp.Delay System Objects.Maps to RAM in HDL code under specific conditions. See RAM Mapping Requirements for Persistent Arrays and System object Properties.
Address generation and port mappingUser specifiedAutomaticAutomatic
Access schedulingUser specifiedAutomatically inferredAutomatically inferred
OverclockingNoneNoneLocal multirate if access schedule requires it.
Latency with respect to simulation in MATLAB®.002 cycles if local multirate; 1 cycle otherwise.
RAM typeUser specifiedDual portDual port