Copyright 2024 Massachusetts Institute of Technology

CEP-DSP: Core blocks

The core DSP blocks (DFT/IDFT/IIR/FIR) were originally generated using the free online hardware generators provided by the Spiral Project.

Generator Websites

• DFT/iDFT: Spiral Project DFT Gen
• IIR/FIR: Spiral Project Filter Gen

Generator Settings

• Note: We indicate deviations from the default generator setting as modified

• DFT/iDFT:

Core(s)	DFT	IDFT
Problem Specification
Transform Size	64	64
Direction	Forward	Inverse
Data type	Fixed Point	Fixed Point
	16 bits	16 bits
	unscaled	unscaled
Parameters Controlling Implementation
Architecture	fully streaming	fully streaming
radix	2	2
streaming width	2	2
data ordering	Natural in / natural out	Natural in / natural out
BRAM budget	1000	1000

• IIR/FIR

Core(s)	IIR	FIR
Example Filter	Custom Filter	Custom Filter
Filter Taps a_k	1.000000e+000	1
	8.274631e-016	1
	1.479294e+000	0
	1.089388e-015	0
	7.013122e-001	0
	4.861197e-016	0
	1.262132e-001	0
	9.512539e-017	0
	7.898376e-003	0
	-4.496047e-018	0
	1.152699e-004	0
	-6.398766e-021	0
Filter Taps b_k	1.618571e-003	1.618571e-003
	1.780428e-002	1.780428e-002
	8.902138e-002	8.902138e-002
	2.670642e-001	2.670642e-001
	5.341283e-001	5.341283e-001
	7.477796e-001	7.477796e-001
	7.477796e-001	7.477796e-001
	5.341283e-001	5.341283e-001
	2.670642e-001	2.670642e-001
	8.902138e-002	8.902138e-002
	1.780428e-002	1.780428e-002
	1.618571e-003	1.618571e-003
Fractional bits	8	8
Bitwidth	32	32
Module Name	IIR_filter	FIR_filter
Input Data	inData	inData
Register Input	Yes	Yes
Output Data	outData	outData
Register Output	Yes	Yes
Clock Name	clk	clk
reset	negedge	negedge
Filter Form	I	I
Debug Output	Off	Off

Incorporating the Generated Source Files

Generated source for the DFT and IDFT cores should be placed in <CEP ROOT>/generators/mitll-blocks/src/main/resources/vsrc/generated_dsp_code.

• DFT
  • Save the generated Verilog file to dft_top.v
  • Remove the testbench module from the generated Verilog file.
• iDFT
  • Save the generated Verilog file to idft_top.v
  • Edit idft_top.v. Rename the dft_top module to idft_top
  • Remove the testbench module from the generated Verilog file.
• IIR (already included in repo)
  • Save the generated Verilog file to IIR_filter.v
• FIR (already included in repo)
  • Save the generated Verilog file to FIR_filter.v

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