Use Cases
- AXI-Stream datapath integration where module boundaries need explicit ready/valid behavior.
- Reusable FPGA DSP pipelines that need fixed-point, timing-aware implementation.
- Memory-mapped control/status integration with software-visible register maps.
Block Diagram
VHDL Include And Instantiation Template
File Header
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
library radhdl;
-- Direct entity instantiation below does not require importing the entity name.
use radhdl.dsp.all;
-- Narrower alternative: use radhdl.dsp_transform.all;Component Declaration
component raddsp_axis_gain is
generic (
VENDOR : string := "xilinx";
DEVICE_FAMILY : string := "generic";
DATA_WIDTH : positive := 16;
COEFF_WIDTH : positive := 18;
COEFF_FRAC_BITS : natural := 15;
CHANNEL_COUNT : positive := 1
);
port (
m_axis_tvalid : out std_logic;
m_axis_tready : in std_logic;
m_axis_tdata : out std_logic_vector((CHANNEL_COUNT * DATA_WIDTH) - 1 downto 0);
m_axis_tlast : out std_logic;
s_axis_tvalid : in std_logic;
s_axis_tready : out std_logic;
s_axis_tdata : in std_logic_vector((CHANNEL_COUNT * DATA_WIDTH) - 1 downto 0);
s_axis_tlast : in std_logic;
clk : in std_logic;
rst : in std_logic;
gain_i : in std_logic_vector((CHANNEL_COUNT * COEFF_WIDTH) - 1 downto 0)
);
end component;Direct Entity Instantiation
u_raddsp_axis_gain : entity radhdl.raddsp_axis_gain
generic map (
VENDOR => "xilinx",
DEVICE_FAMILY => "generic",
DATA_WIDTH => 16,
COEFF_WIDTH => 18,
COEFF_FRAC_BITS => 15,
CHANNEL_COUNT => 1
)
port map (
m_axis_tvalid => <m_axis_tvalid_signal>,
m_axis_tready => <m_axis_tready_signal>,
m_axis_tdata => <m_axis_tdata_signal>,
m_axis_tlast => <m_axis_tlast_signal>,
s_axis_tvalid => <s_axis_tvalid_signal>,
s_axis_tready => <s_axis_tready_signal>,
s_axis_tdata => <s_axis_tdata_signal>,
s_axis_tlast => <s_axis_tlast_signal>,
clk => <clk_signal>,
rst => <rst_signal>,
gain_i => <gain_i_signal>
);Generics
| Name | Type | Default | Description |
|---|---|---|---|
| VENDOR | string | "xilinx" | Selects the vendor-specific implementation path, usually XILINX for DSP48/XPM-backed builds or generic for portable RTL. |
| DEVICE_FAMILY | string | "generic" | Identifies the target FPGA family so wrappers can choose the correct primitive or conservative portable behavior. |
| DATA_WIDTH | positive | 16 | Sets the bit width for DATA WIDTH values carried by this module. |
| COEFF_WIDTH | positive | 18 | Sets the bit width for COEFF WIDTH values carried by this module. |
| COEFF_FRAC_BITS | natural | 15 | Sets coefficient precision or coefficient count for the fixed-point DSP operation. |
| CHANNEL_COUNT | positive | 1 | Sets the number of parallel sample lanes processed per handshake beat. |
Ports
| Name | Direction | Type | Description |
|---|---|---|---|
| m_axis_tvalid | out | std_logic | Output AXI-stream valid qualifier for the current result beat. |
| m_axis_tready | in | std_logic | Output AXI-stream ready input from the downstream block. |
| m_axis_tdata | out | std_logic_vector((CHANNEL_COUNT * DATA_WIDTH) - 1 downto 0) | Output AXI-stream payload containing packed processed result lanes. |
| m_axis_tlast | out | std_logic | Output AXI-stream frame marker aligned with the processed result beat. |
| s_axis_tvalid | in | std_logic | Input AXI-stream valid qualifier for the current sample beat. |
| s_axis_tready | out | std_logic | Input AXI-stream ready response indicating this block can accept a beat. |
| s_axis_tdata | in | std_logic_vector((CHANNEL_COUNT * DATA_WIDTH) - 1 downto 0) | Input AXI-stream payload containing packed sample or feature lanes. |
| s_axis_tlast | in | std_logic | Input AXI-stream frame marker for the final beat of a frame. |
| clk | in | std_logic | Clock for the associated synchronous logic and handshake domain. |
| rst | in | std_logic | Active-high synchronous reset for this clock domain. |
| gain_i | in | std_logic_vector((CHANNEL_COUNT * COEFF_WIDTH) - 1 downto 0) | Packed fixed-point gain coefficient input, one coefficient per channel. |
Measured Implementation Metrics
Metrics are generated by RadBuild from real Vivado synthesis reports for representative device targets. Raw report paths are preserved in the checked summary JSON.
| Part | Clock ns | MHz | LUTs | FFs | BRAM tiles | DSPs | Setup WNS ns | Hold WHS ns | Generics | Summary |
|---|---|---|---|---|---|---|---|---|---|---|
| xc7a35tcsg324-1 | 10.0 | 100.0 | - | - | - | - | - | - | - | projects/synth_reports/raddsp_axis_gain/xc7a35tcsg324-1/synth_summary.json |
| xc7a35tcsg324-2 | 10.0 | 100.0 | 27 | 59 | 0 | 1 | 6.452 | 0.136 | - | projects/synth_reports/raddsp_axis_gain/xc7a35tcsg324-2/synth_summary.json |
| xc7z020clg400-1 | 10.0 | 100.0 | 27 | 59 | 0 | 1 | 5.421 | 0.144 | - | projects/synth_reports/raddsp_axis_gain/xc7z020clg400-1/synth_summary.json |
| xc7z020clg400-2 | 10.0 | 100.0 | 27 | 59 | 0 | 1 | 6.734 | 0.138 | - | projects/synth_reports/raddsp_axis_gain/xc7z020clg400-2/synth_summary.json |
| xc7z020clg400-3 | 10.0 | 100.0 | - | - | - | - | - | - | - | projects/synth_reports/raddsp_axis_gain/xc7z020clg400-3/synth_summary.json |
| xczu3eg-sfvc784-1-e | 6.667 | 149.993 | 27 | 59 | 0 | 1 | 4.898 | -0.063 | DEVICE_FAMILY=ultrascaleplus | projects/synth_reports/raddsp_axis_gain/xczu3eg-sfvc784-1-e/synth_summary.json |
| xczu3eg-sfvc784-2-e | 6.667 | 149.993 | 27 | 59 | 0 | 1 | 5.545 | 0.146 | DEVICE_FAMILY=ultrascaleplus | projects/synth_reports/raddsp_axis_gain/xczu3eg-sfvc784-2-e/synth_summary.json |
Register Interfaces
No fixed register map was found; this section documents the exposed register/control interface ports.
| Interface | Directions | Signals | Representative ports |
|---|---|---|---|
| M_AXIS | in, out | 4 | m_axis_tvalid, m_axis_tready, m_axis_tdata, m_axis_tlast |
| S_AXIS | in, out | 4 | s_axis_tvalid, s_axis_tready, s_axis_tdata, s_axis_tlast |
Testbenches
tb_raddsp_axis_smoke
Self-checking or stimulus-focused testbench for axis smoke. Exercises representative handshakes, reset behavior, frame boundaries, and numeric corner cases for regression runs.
Interface Timing Diagram
M_AXIS interface signals
M_AXIS Interface Waveform
S_AXIS interface signals
S_AXIS Interface Waveform
Sources
- dsp/hdl/raddsp/src/raddsp_axis_gain.vhd
