Advanced FIR Filter

Overview

A FIR (Finite Impulse Response) filter performs a convolution of an input data sequence with the filter's impulse response (the discrete- time inverse Fourier transform of its desired frequency response), which is stored in memory. The equation for performing the convolution is given by

where y_n is the filter output at sample n, x_n-i is the value of the filter input i samples in the past, and h_i is the ith value of the filter impulse response.

The Lattice Advanced FIR Filter v.4.0 IP core is an advanced, widely configurable, multi-channel FIR filter, implemented using high-performance sysDSP^TM blocks available in Lattice devices.  In addition to single rate filters, the IP core also supports a range of poly-phase decimation and interpolation filters.  By specifying the number of multipliers, designers can control tradeoffs between utilization and throughput, enable the optimal design for their requirements.  The IP core uses full internal precision while allowing variable output precision sith several choices for saturation and rounding.  The coefficients of the filter can be specified at generation time with the option of reloading them during run-time through the input ports.

Features

• Variable Number of Taps, up to 2048
• Input and Coefficients Widths of 4 to 32 Bits
• Multi-channel support for up to 256 Channels
• Decimation and Interpolation Ratios from 2 to 256
• Configurable Parallelism from Full to Serial
• Signed or Unsigned Data and Coefficients
• Coefficients Symmetry Optimization
• Reloadable Coefficients Support
• Full Precision Arithmetic
• Selectable Output Width and Precision
• Selectable Overflow - Wrap-around or Saturation
• Selectable Rounding - Truncation, Round towards Zero, Round Away from Zero, Round to Nearest and Convergent Rounding
• Multi-channel Operation with Per-channel Coefficients and Parameters
• Channel_in/channel_out Ports to Facilitate System Timing
  

 

Performance and Resource Utilization

Results for LatticeECP2¹

Mode	SLICEs	LUTs	Registers	sysDSP blocks	sysMEM EBRs	fMAX (MHz)
4 channels, 64 taps,  multiplier	122	122	242	1	2	370
1 channels, 32 taps, 32 multipliers	415	268	806	8	0	309
1 channel, 32 taps, 8 multiplies	378	530	622	2	0	322

¹ Performance and utilization characteristics are generated targeting LFE2-50E-7F672C using Lattice's ispLEVER® v.7.1 software. When using this IP core in a different density, speed, or grade within the LatticeECP2 family or in a different software version, performance may vary.

Results for LatticeECP2M¹

Mode	SLICEs	LUTs	Registers	sysDSP blocks	sysMEM EBRs	fMAX (MHz)
4 channels, 64 taps,  multiplier	122	122	242	1	2	370
1 channels, 32 taps, 32 multipliers	415	268	806	8	0	298
1 channel, 32 taps, 8 multiplies	378	530	622	0	0	325

¹ Performance and utilization characteristics are generated targeting LFE2M-50E-7F672C using Lattice's ispLEVER® v.7.1 software. When using this IP core in a different density, speed, or grade within the LatticeECP2M family or in a different software version, performance may vary.

Results for LatticeXP2¹

Mode	SLICEs	LUTs	Registers	sysDSP blocks	sysMEM EBRs	fMAX (MHz)
4 channels, 64 taps,  multiplier	122	122	242	1	2	314
1 channels, 32 taps, 32 multipliers	415	268	806	8	0	314
1 channel, 32 taps, 8 multiplies	378	530	622	2	0	324

¹ Performance and utilization characteristics are generated targeting LFXP2-40E-7F672C using Lattice's ispLEVER® v.7.1 software. When using this IP core in a different density, speed, or grade within the LatticeXP2 family or in a different software version, performance may vary.

Ordering Information

Part Numbers:
For LatticeECP2: FIR-COMP-P2-U4
For LatticeECP2m: FIR-COMP-PM-U4
For LatticeXP2:  FIR-COMP-X2-U4

To download a full evaluation version of this IP, please go to the Lattice IP Server tab in the IPexpress Main Window. All ispLeverCORE IP modules available for download are visible on this tab.

To find out how to purchase the Advanced FIR Filter IP v.4.0 Core, please contact your local Lattice Sales Office.