secded_decode.md

secded_decode

Property	Value
Kind	module
RTL source	rtl/base/ecc_secded.sv
Availability	Synthesizable RTL

Summary

Extended-Hamming SECDED decoder, corrector, and error classifier.

Functional Behavior

Computes a Hamming syndrome and overall parity, corrects a correctable single-bit fault, reports an overall-parity-only error, and flags uncorrectable double errors without changing the codeword.

Suitable Applications

Use on protected memory reads and protected interconnect payloads.

Parameters

The declaration below is canonical; retain the RTL-enforced parameter range.

Parameter	Declaration
DATA_WIDTH	parameter int DATA_WIDTH = 64

Interface Definition

module secded_decode #(
    parameter int DATA_WIDTH = 64
) (
    input logic [DATA_WIDTH+secded_layout_pkg::check_bits_for(DATA_WIDTH):0] code_i,
    output logic [DATA_WIDTH-1:0] data_o,
    output logic [secded_layout_pkg::check_bits_for(DATA_WIDTH)-1:0] syndrome_o,
    output logic corrected_o,
    output logic overall_parity_error_o,
    output logic uncorrectable_o
);

Port Summary

Signal	Direction	Declaration
code_i	input	input logic [DATA_WIDTH+secded_layout_pkg::check_bits_for(DATA_WIDTH):0] code_i
data_o	output	output logic [DATA_WIDTH-1:0] data_o
syndrome_o	output	output logic [secded_layout_pkg::check_bits_for(DATA_WIDTH)-1:0] syndrome_o
corrected_o	output	output logic corrected_o
overall_parity_error_o	output	output logic overall_parity_error_o
uncorrectable_o	output	output logic uncorrectable_o

Integration and Use

Treat decoded data as invalid when uncorrectable_o is high and use exactly the matching encoder geometry.

secded_decode #(
    .DATA_WIDTH(DATA_WIDTH)
) u_secded_decode (
    .code_i(code_i),
    .data_o(data_o),
    .syndrome_o(syndrome_o),
    .corrected_o(corrected_o),
    .overall_parity_error_o(overall_parity_error_o),
    .uncorrectable_o(uncorrectable_o)
);

Dependencies and Verification

The linked RTL source is the implementation authority and contains local assertions for unsupported parameter combinations. See docs/design.md for repository-wide CDC, reset, stream, and storage contracts, and docs/verification.md for the verification matrix.