Table 3–5, Table 3–6 – Altera FIR Compiler User Manual

Page 37

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Chapter 3: Parameter Settings

3–13

Specify the Architecture Specification

© May 2011

Altera Corporation

FIR Compiler User Guide

Table 3–5. Fully Serial Filter Architecture

(Note 1)

Parameter

Description

Data Storage

Specifies the device resources used for data storage. You can select Logic Cells, M512, M4K,
M-RAM, MLAB, M9K, M144K, or Auto. If you select Auto, the Quartus II software may store data in
logic cells or memory, depending on the resources in the selected device, the size of the data
storage, and the number of input channels.

Coefficient Storage

Specifies the device resources used for coefficient storage. You can select Logic Cells, M512,
M4K, MLAB, M9K, or Auto. If you select Auto, the Quartus II software automatically selects the
most appropriate memory block size for the selected device.

The option list changes depending on which device you select. Selecting embedded memory
reduces logic cell usage and may increase the speed of the filter.

Force Non-Symmetric
Structure

If you want to create a design that uses both symmetric and non-symmetric coefficients, turn on
this option.

Symmetric algorithms require an extra clock cycle per calculation cycle, which leads to lower
throughput.

Coefficients Reload

If you want to change coefficients, turn on this option. This option is available when you choose to
store coefficients in embedded memory.

Selecting this option increases resource usage, turns off several optimization schemes, and adds
additional input ports to the filter.

Pipeline Level

Creates a higher performance filter with a resource usage increase.

Use Single Clock

Use this option when creating designs with DSP Builder. This option is only available when
Coefficients Reload is selected and M512, M4K, MLAB or M9K is specified in Coefficient Storage.

This option ties the

coef_in_clk

and

clk

signals together.

Note to

Table 3–5

:

(1) The input data bit width should be greater than or equal to four.

Table 3–6. Multibit Serial Filter Architecture (Part 1 of 2)

(Note 1)

Parameters

Description

Number of Serial
Units

Specifies the number of serial units needed to make the filter. You can select 2, 3, or 4. The
calculation cycles of each result are reduced to one nth of the corresponding serial filter, where n is
the number of serial units. Correspondingly, there is an increase in resource utilization.

Data Storage

Specifies the device resources used for data storage. You can select Logic Cells, M512, M4K, M-
RAM
, MLAB, M9K, M144K, or Auto. If you select Auto, the Quartus II software selects the type of
embedded memory blocks, depending on the resources in the selected device, the size of the data
storage, the number of clock cycles to compute a result, and the number of input channels.

The option list changes depending on which device you select and whether you select multirate
(interpolation or decimation). Choosing embedded memory reduces logic cell usage and may
increase the speed of the filter.

Coefficient Storage

Specifies the device resources used for coefficient storage. You can select Logic Cells, M512, M4K,
MLAB, M9K, or Auto. If you select Auto, the Quartus II software automatically selects the most
appropriate memory block size for the selected device.

The option list changes depending on which device you select. Selecting embedded memory
reduces logic cell usage and may increase the speed of the filter.

Force Non-Symmetric
Structure

If you want to create a design that uses both symmetric and non-symmetric coefficients, turn on
this option.

Symmetric algorithms require an extra clock cycle per calculation cycle, which leads to lower
throughput.

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