FIR II IP Core: User Guide

ID 683208
Date 8/14/2023
Public

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3.5.1.2. Using Dual-port RAM Threshold

This FIR II IP core threshold is trade-off between small and medium RAM blocks. This threshold is similar to the Memory Block Threshold except that it applies only to the dual-port memories.

The IP core implements any dual-port memory in a block memory rather than logic elements, but for some device families different sizes of block memory may be available. The threshold value determines which medium-size RAM memory blocks IP core implements instead of small-memory RAM blocks. For example, the threshold that determines whether to use M9K blocks rather than MLAB blocks on Stratix  IV devices.

  1. Set the default threshold value, to implement dual memories greater than 1,280 bits as M9K blocks and dual memories less than or equal to 1,280 bits as MLABs.
  2. Change this threshold to a lower value such as 200, to implement dual memories greater than 200 bits as M9K blocks and dual memories less than or equal to 200 bits as MLAB blocks.
    Note: For device families with only one type of memory block, this threshold has no effect.