common/docs/reference/bus/address_range_decoder.md

address_range_decoder

Property	Value
Kind	module
RTL source	rtl/bus/address_advanced.sv
Availability	Synthesizable RTL

Summary

Inclusive address-range decoder.

Functional Behavior

Inclusive address-range decoder. It classifies the presented address using the configured decode rule and returns the documented selection/match result combinationally.

Suitable Applications

Use for memory maps, peripheral selection, firewall regions, and target routing.

Parameters

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

Parameter	Declaration
ADDR_WIDTH	parameter int ADDR_WIDTH = 32
RULES	parameter int RULES = 4
TARGETS	parameter int TARGETS = 4
INDEX_WIDTH	parameter int INDEX_WIDTH = (TARGETS > 1) ? $clog2(TARGETS) : 1

Interface Definition

module address_range_decoder #(
    parameter int ADDR_WIDTH  = 32,
    parameter int RULES       = 4,
    parameter int TARGETS     = 4,
    parameter int INDEX_WIDTH = (TARGETS > 1) ? $clog2(TARGETS) : 1
) (
    input  logic [ ADDR_WIDTH-1:0]                  addr_i,
    input  logic [      RULES-1:0][INDEX_WIDTH-1:0] target_i,
    input  logic [      RULES-1:0][ ADDR_WIDTH-1:0] first_i,
    input  logic [      RULES-1:0][ ADDR_WIDTH-1:0] last_i,
    input  logic                                    updating_i,
    input  logic                                    default_enable_i,
    input  logic [INDEX_WIDTH-1:0]                  default_target_i,
    output logic [    TARGETS-1:0]                  select_o,
    output logic [INDEX_WIDTH-1:0]                  target_o,
    output logic                                    valid_o,
    output logic                                    error_o
);

Port Summary

Signal	Direction	Declaration
addr_i	input	input logic [ ADDR_WIDTH-1:0] addr_i
target_i	input	input logic [ RULES-1:0][INDEX_WIDTH-1:0] target_i
first_i	input	input logic [ RULES-1:0][ ADDR_WIDTH-1:0] first_i
last_i	input	input logic [ RULES-1:0][ ADDR_WIDTH-1:0] last_i
updating_i	input	input logic updating_i
default_enable_i	input	input logic default_enable_i
default_target_i	input	input logic [INDEX_WIDTH-1:0] default_target_i
select_o	output	output logic [ TARGETS-1:0] select_o
target_o	output	output logic [INDEX_WIDTH-1:0] target_o
valid_o	output	output logic valid_o
error_o	output	output logic error_o

Integration and Use

Check overlaps and priority deliberately. Decode does not by itself complete or validate a bus transaction.

address_range_decoder #(
    .ADDR_WIDTH(ADDR_WIDTH),
    .RULES(RULES),
    .TARGETS(TARGETS),
    .INDEX_WIDTH(INDEX_WIDTH)
) u_address_range_decoder (
    .addr_i(addr_i),
    .target_i(target_i),
    .first_i(first_i),
    .last_i(last_i),
    .updating_i(updating_i),
    .default_enable_i(default_enable_i),
    .default_target_i(default_target_i),
    .select_o(select_o),
    .target_o(target_o),
    .valid_o(valid_o),
    .error_o(error_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.